Skip to main content

CWE-191

Integer Underflow

449 CVEs Avg CVSS 7.2 MITRE
48
CRITICAL
243
HIGH
140
MEDIUM
17
LOW
62
POC
2
KEV

Monthly

CVE-2026-48503 Oct 16, 15:44 HIGH PATCH This Week

An unauthenticated remote client can disclose stale memory contents from a libIEC61850 server running the MMS file service, because a crafted out-of-range initialPosition in a fileOpen request drives an unsigned integer underflow in the fileRead path and produces an oversized response that appends leftover bytes from the reused connection buffer. All versions prior to 1.6.2 are affected, and exploitation requires only network reachability to the MMS/TCP listener with the file service enabled - a non-default configuration. No public exploit code has been identified at time of analysis and there is no confirmed active exploitation, though the independently assessed confidentiality impact is moderate rather than catastrophic since the attacker cannot select or guarantee the sensitivity of the leaked bytes.

Information Disclosure Integer Overflow Libiec61850 Mz Automation
NVD GitHub
CVSS 3.1
7.5
CVE-2026-101938 Oct 14, 16:41 HIGH PATCH This Week

An integer underflow in the srxpfe forwarding-plane daemon of Junos OS and Junos OS Evolved on SRX Series firewalls allows an unauthenticated attacker on an adjacent network segment to trigger a denial of service by sending an ICMP message tied to an SVR (Secure Vector Routing) carrier session. Affected deployments are those running SVR/carrier-session functionality on SRX platforms, where successful exploitation degrades or halts packet forwarding; the CVSS 4.0 base score of 7.1 reflects high availability impact with no confidentiality or integrity loss (assessed CVSS 3.1: AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). There is no public exploit code and no confirmed active exploitation (no CISA KEV listing) at time of analysis, but the attack requires only Layer 2 adjacency and no credentials or user interaction, so any SRX device with SVR sessions reachable from an untrusted adjacent segment should be treated as exposed.

Denial Of Service Integer Overflow Juniper Junos Os Evolved Junos Os +1
NVD VulDB
CVSS 4.0
7.1
EPSS
0.3%
CVE-2026-101980 Oct 14, 16:17 CRITICAL PATCH Act Now

Integer underflow in the Junos OS kernel can crash a device when the Extended Echo feature (RFC 8335 ICMP probing) is configured, allowing a remote, unauthenticated attacker to cause a denial of service; the independent assessment rates the impact as availability-only (CVSS 3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). The exposure is bounded by the Extended Echo precondition, and no public exploit identified at time of analysis. Juniper advisory JSA112188 should be used to identify affected and fixed releases.

Denial Of Service Integer Overflow Juniper Junos Os Juniper Networks
NVD
CVSS 4.0
9.3
EPSS
0.5%
CVE-2026-110714 Oct 14, 15:01 HIGH POC PATCH This Week

Malicious SMB servers can crash libsmb2 clients through version 6.2 by returning a crafted SMB2 QUERY_INFO reply that triggers a heap out-of-bounds read during security descriptor decoding. The bug is an integer underflow in decode_acl: an ACL whose AclSize field is smaller than 8 bytes underflows the remaining-buffer counter, bypassing the per-ACE bounds check and producing an availability-only denial of service with no code execution, data disclosure, or integrity loss. Publicly available exploit code exists, but there is no confirmed active exploitation (CISA KEV), and the attacker must either control the SMB server the victim connects to or hold a man-in-the-middle position on an unsigned SMB session (UI:P/UI:R), making this a moderate-priority availability issue rather than an emergency.

Denial Of Service Integer Overflow Libsmb2
NVD GitHub
CVSS 4.0
7.1
EPSS
0.5%
CVE-2026-97746 Oct 13, 19:22 HIGH PATCH Exploit Unlikely This Week

Remote code execution in Microsoft Excel is possible when a user opens a specially crafted spreadsheet, because an integer underflow (CWE-191) in Office's document handling wraps a value and leads to memory corruption exploitable for code execution in the context of the opening user. No authentication is required on the target (PR:N) and the file can be delivered over the network via email, a link, or a shared document, but exploitation depends on the victim opening the file (UI:R), and no server-side or zero-click path is indicated. Microsoft has released fixed builds (for example Office LTSC 2021 16.0.14334.20974 and Office LTSC 2024 16.0.17932.21056), and no public exploit identified at time of analysis; treat this as a high-priority, patch-worthy issue rather than an emergency given the absence of exploitation signals.

Authentication Bypass Integer Overflow Microsoft 365 Apps Office Online Server +3
NVD
CVSS 3.1
8.8
EPSS
0.7%
CVE-2026-96844 Oct 13, 19:21 HIGH PATCH Exploit Unlikely This Week

Privilege escalation in the Microsoft Bluetooth Driver lets an attacker within Bluetooth radio range who already holds low-privilege authenticated access escalate to full compromise of confidentiality, integrity, and availability (CVSS 8.0, AV:A/PR:L/UI:N). Affected builds span Windows 10 (1607, 1809, 21H2, 22H2), Windows 11 (23H2, 24H2, 25H2, 26H1, 26H2), and Windows Server 2012 through 2025 that have not been updated to the fixed build numbers in the vendor advisory. No public exploit has been identified at time of analysis, and CISA's SSVC rates exploitation as none and automatable as no, although technical impact is total; exploitation also requires Bluetooth to be enabled and the attacker to be physically adjacent, so internet-facing systems are not at risk.

Windows Integer Overflow Microsoft Windows 10 1607 Windows 10 1809 +12
NVD
CVSS 3.1
8.0
EPSS
0.5%
CVE-2026-83869 Oct 13, 19:20 CRITICAL PATCH Exploit Unlikely Act Now

Remote code execution in the Windows DNS Server role is achievable by an unauthenticated, network-positioned attacker who can send crafted DNS traffic to an affected host, as described by an integer underflow (CWE-191) defect in how the service handles attacker-influenced input. Per the assessed CVSS vector (AV:N/AC:L/PR:N/UI:N, C:H/I:H/A:H) exploitation is remote, low-complexity, requires no credentials and no user interaction, and yields total loss of confidentiality, integrity and availability on the DNS server - the practical limit being that only Windows systems actually running the DNS Server role (Windows Server 2012 through 2025, plus Windows 10/11 builds where the role is installed) are exposed. Microsoft has released vendor patches through the MSRC update guide and the EUVD advisory maps fixed builds per platform; there is no KEV listing and no public exploit identified at time of analysis, and no EPSS score was supplied with the source data. CISA's SSVC assessment records Exploitation: none, Automatable: yes, Technical Impact: total, which supports treating this as a genuine high-priority patching item rather than a high-score-but-low-real-risk case.

Integer Overflow Microsoft Windows 10 1607 Windows 10 1809 Windows 10 21h2 +11
NVD
CVSS 3.1
9.8
EPSS
0.6%
CVE-2026-83855 Oct 13, 19:20 HIGH PATCH Exploit Unlikely This Week

Denial of service in the Windows WLAN Service affects Windows 11 builds 23H2 through 26H2 and Windows Server 2025, where an integer underflow in the wireless networking component can be triggered by an unauthenticated attacker to exhaust or crash the service. Per the assessed CVSS vector (AV:N/AC:L/PR:N/UI:N, C:N/I:N/A:H), no credentials or user interaction are required and the sole impact is loss of availability, with the practical gating factor being reachability of the WLAN stack rather than direct internet exposure; no public exploit code has been identified at time of analysis, CISA SSVC records Exploitation: none, and vendor patches are available. CISA's SSVC also flags the issue as Automatable: yes with partial technical impact, making it a moderate-priority patching item for wireless-capable endpoints and servers.

Windows Integer Overflow Microsoft
NVD
CVSS 3.1
7.5
EPSS
1.2%
CVE-2026-83838 Oct 13, 19:20 HIGH PATCH Exploit Unlikely This Week

Privilege escalation in the Windows Bluetooth A2DP audio-streaming driver allows an attacker who already holds low-privilege authorized access on a host - and who is within Bluetooth radio range - to induce an integer underflow in driver arithmetic and leverage the resulting memory-handling error to gain elevated rights, with high impact across confidentiality, integrity, and availability. The 8.0 High severity rating (CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) is consistent with the CISA SSVC assessment of 'total' technical impact, and reflects two important constraints: the attack vector is adjacent-network only and the attacker must already have a foothold on the target, so this is not remote unauthenticated exploitation, and no user interaction is required. Microsoft has released updates through the MSRC update guide, CISA's SSVC exploitation value is 'none', and no public exploit code was identified at time of analysis. Unpatched Windows 10, Windows 11 (through 26H2), and Windows Server 2016 through 2025 builds are affected, but only hosts with Bluetooth enabled and within radio proximity of the attacker are exposed.

Windows Information Disclosure Integer Overflow Microsoft
NVD
CVSS 3.1
8.0
EPSS
0.5%
CVE-2026-70064 Oct 13, 19:19 HIGH PATCH Exploit Unlikely This Week

Integer underflow in the Windows Kerberos authentication component allows a locally authenticated attacker to elevate privileges on an affected host, giving full control over confidentiality, integrity, and availability of the machine. Exploitation requires a prior foothold: the attacker must already hold a valid low-privileged local account (PR:L, AV:L), and no user interaction is needed once that access exists; the flaw is not remotely reachable and SSVC rates it non-automatable, so it cannot be driven at mass or wormable scale. No public exploit code has been identified at time of analysis and there is no confirmed active exploitation (CISA KEV), but a vendor patch is available from Microsoft and should be applied to the extensive list of affected Windows 10, Windows 11, and Windows Server builds.

Windows Information Disclosure Integer Overflow Microsoft
NVD
CVSS 3.1
7.8
EPSS
0.3%
CVSS 7.5
HIGH PATCH This Week

An unauthenticated remote client can disclose stale memory contents from a libIEC61850 server running the MMS file service, because a crafted out-of-range initialPosition in a fileOpen request drives an unsigned integer underflow in the fileRead path and produces an oversized response that appends leftover bytes from the reused connection buffer. All versions prior to 1.6.2 are affected, and exploitation requires only network reachability to the MMS/TCP listener with the file service enabled - a non-default configuration. No public exploit code has been identified at time of analysis and there is no confirmed active exploitation, though the independently assessed confidentiality impact is moderate rather than catastrophic since the attacker cannot select or guarantee the sensitivity of the leaked bytes.

Information Disclosure Integer Overflow Libiec61850 +1
NVD GitHub
EPSS 0% CVSS 7.1
HIGH PATCH This Week

An integer underflow in the srxpfe forwarding-plane daemon of Junos OS and Junos OS Evolved on SRX Series firewalls allows an unauthenticated attacker on an adjacent network segment to trigger a denial of service by sending an ICMP message tied to an SVR (Secure Vector Routing) carrier session. Affected deployments are those running SVR/carrier-session functionality on SRX platforms, where successful exploitation degrades or halts packet forwarding; the CVSS 4.0 base score of 7.1 reflects high availability impact with no confidentiality or integrity loss (assessed CVSS 3.1: AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). There is no public exploit code and no confirmed active exploitation (no CISA KEV listing) at time of analysis, but the attack requires only Layer 2 adjacency and no credentials or user interaction, so any SRX device with SVR sessions reachable from an untrusted adjacent segment should be treated as exposed.

Denial Of Service Integer Overflow Juniper +3
NVD VulDB
EPSS 0% CVSS 9.3
CRITICAL PATCH Act Now

Integer underflow in the Junos OS kernel can crash a device when the Extended Echo feature (RFC 8335 ICMP probing) is configured, allowing a remote, unauthenticated attacker to cause a denial of service; the independent assessment rates the impact as availability-only (CVSS 3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). The exposure is bounded by the Extended Echo precondition, and no public exploit identified at time of analysis. Juniper advisory JSA112188 should be used to identify affected and fixed releases.

Denial Of Service Integer Overflow Juniper +2
NVD
EPSS 1% CVSS 7.1
HIGH POC PATCH This Week

Malicious SMB servers can crash libsmb2 clients through version 6.2 by returning a crafted SMB2 QUERY_INFO reply that triggers a heap out-of-bounds read during security descriptor decoding. The bug is an integer underflow in decode_acl: an ACL whose AclSize field is smaller than 8 bytes underflows the remaining-buffer counter, bypassing the per-ACE bounds check and producing an availability-only denial of service with no code execution, data disclosure, or integrity loss. Publicly available exploit code exists, but there is no confirmed active exploitation (CISA KEV), and the attacker must either control the SMB server the victim connects to or hold a man-in-the-middle position on an unsigned SMB session (UI:P/UI:R), making this a moderate-priority availability issue rather than an emergency.

Denial Of Service Integer Overflow Libsmb2
NVD GitHub
EPSS 1% CVSS 8.8
HIGH PATCH Exploit Unlikely This Week

Remote code execution in Microsoft Excel is possible when a user opens a specially crafted spreadsheet, because an integer underflow (CWE-191) in Office's document handling wraps a value and leads to memory corruption exploitable for code execution in the context of the opening user. No authentication is required on the target (PR:N) and the file can be delivered over the network via email, a link, or a shared document, but exploitation depends on the victim opening the file (UI:R), and no server-side or zero-click path is indicated. Microsoft has released fixed builds (for example Office LTSC 2021 16.0.14334.20974 and Office LTSC 2024 16.0.17932.21056), and no public exploit identified at time of analysis; treat this as a high-priority, patch-worthy issue rather than an emergency given the absence of exploitation signals.

Authentication Bypass Integer Overflow Microsoft +5
NVD
EPSS 0% CVSS 8.0
HIGH PATCH Exploit Unlikely This Week

Privilege escalation in the Microsoft Bluetooth Driver lets an attacker within Bluetooth radio range who already holds low-privilege authenticated access escalate to full compromise of confidentiality, integrity, and availability (CVSS 8.0, AV:A/PR:L/UI:N). Affected builds span Windows 10 (1607, 1809, 21H2, 22H2), Windows 11 (23H2, 24H2, 25H2, 26H1, 26H2), and Windows Server 2012 through 2025 that have not been updated to the fixed build numbers in the vendor advisory. No public exploit has been identified at time of analysis, and CISA's SSVC rates exploitation as none and automatable as no, although technical impact is total; exploitation also requires Bluetooth to be enabled and the attacker to be physically adjacent, so internet-facing systems are not at risk.

Windows Integer Overflow Microsoft +14
NVD
EPSS 1% CVSS 9.8
CRITICAL PATCH Exploit Unlikely Act Now

Remote code execution in the Windows DNS Server role is achievable by an unauthenticated, network-positioned attacker who can send crafted DNS traffic to an affected host, as described by an integer underflow (CWE-191) defect in how the service handles attacker-influenced input. Per the assessed CVSS vector (AV:N/AC:L/PR:N/UI:N, C:H/I:H/A:H) exploitation is remote, low-complexity, requires no credentials and no user interaction, and yields total loss of confidentiality, integrity and availability on the DNS server - the practical limit being that only Windows systems actually running the DNS Server role (Windows Server 2012 through 2025, plus Windows 10/11 builds where the role is installed) are exposed. Microsoft has released vendor patches through the MSRC update guide and the EUVD advisory maps fixed builds per platform; there is no KEV listing and no public exploit identified at time of analysis, and no EPSS score was supplied with the source data. CISA's SSVC assessment records Exploitation: none, Automatable: yes, Technical Impact: total, which supports treating this as a genuine high-priority patching item rather than a high-score-but-low-real-risk case.

Integer Overflow Microsoft Windows 10 1607 +13
NVD
EPSS 1% CVSS 7.5
HIGH PATCH Exploit Unlikely This Week

Denial of service in the Windows WLAN Service affects Windows 11 builds 23H2 through 26H2 and Windows Server 2025, where an integer underflow in the wireless networking component can be triggered by an unauthenticated attacker to exhaust or crash the service. Per the assessed CVSS vector (AV:N/AC:L/PR:N/UI:N, C:N/I:N/A:H), no credentials or user interaction are required and the sole impact is loss of availability, with the practical gating factor being reachability of the WLAN stack rather than direct internet exposure; no public exploit code has been identified at time of analysis, CISA SSVC records Exploitation: none, and vendor patches are available. CISA's SSVC also flags the issue as Automatable: yes with partial technical impact, making it a moderate-priority patching item for wireless-capable endpoints and servers.

Windows Integer Overflow Microsoft
NVD
EPSS 0% CVSS 8.0
HIGH PATCH Exploit Unlikely This Week

Privilege escalation in the Windows Bluetooth A2DP audio-streaming driver allows an attacker who already holds low-privilege authorized access on a host - and who is within Bluetooth radio range - to induce an integer underflow in driver arithmetic and leverage the resulting memory-handling error to gain elevated rights, with high impact across confidentiality, integrity, and availability. The 8.0 High severity rating (CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) is consistent with the CISA SSVC assessment of 'total' technical impact, and reflects two important constraints: the attack vector is adjacent-network only and the attacker must already have a foothold on the target, so this is not remote unauthenticated exploitation, and no user interaction is required. Microsoft has released updates through the MSRC update guide, CISA's SSVC exploitation value is 'none', and no public exploit code was identified at time of analysis. Unpatched Windows 10, Windows 11 (through 26H2), and Windows Server 2016 through 2025 builds are affected, but only hosts with Bluetooth enabled and within radio proximity of the attacker are exposed.

Windows Information Disclosure Integer Overflow +1
NVD
EPSS 0% CVSS 7.8
HIGH PATCH Exploit Unlikely This Week

Integer underflow in the Windows Kerberos authentication component allows a locally authenticated attacker to elevate privileges on an affected host, giving full control over confidentiality, integrity, and availability of the machine. Exploitation requires a prior foothold: the attacker must already hold a valid low-privileged local account (PR:L, AV:L), and no user interaction is needed once that access exists; the flaw is not remotely reachable and SSVC rates it non-automatable, so it cannot be driven at mass or wormable scale. No public exploit code has been identified at time of analysis and there is no confirmed active exploitation (CISA KEV), but a vendor patch is available from Microsoft and should be applied to the extensive list of affected Windows 10, Windows 11, and Windows Server builds.

Windows Information Disclosure Integer Overflow +1
NVD

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy