Skip to main content
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Identify target with imptcp loaded in non-default framing mode
  2. Delivery
    Connect to exposed TCP syslog ingestion port
  3. Exploit
    Send crafted stream triggering oversize-frame recovery path
  4. Execution
    Cause invalid internal message length computation
  5. Impact
    rsyslogd process terminates

Vulnerability Assessment

Weakness
CWE
CWE-125
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK

1 technique across 1 tactic: Collection

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Sign in to read
Exploitation Conditions

Two server-side configuration prerequisites must both be present for exploitation: first, the optional imptcp input module must be explicitly loaded in rsyslogd's configuration - this module is not enabled by default on RHEL or most distributions; second, a non-default frame delimiting mode must be active for that imptcp listener - the default imptcp framing is explicitly confirmed unaffected. The attacker must have network-level access to the TCP port serving imptcp traffic; no authentication is required once those conditions are met (CVSS PR:N). The primary limiting factor is the rarity of the required configuration combination: most rsyslogd deployments use imtcp or default imptcp framing and are entirely unexposed. No specific operating system platform, user session, or privilege level beyond the module configuration is required.
Impact

The CVSS 7.5 High rating (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) reflects a genuine and directly reachable availability risk - an unauthenticated remote peer can crash the logging daemon with no interaction required from the target system. However, the score must be contextualised against the dual configuration prerequisite: imptcp must be explicitly loaded and configured with a non-default framing mode, a deployment pattern that represents a minority of rsyslogd installations. No EPSS data was provided in available intelligence, but the narrow attack surface implies a modest exploitation probability across the broader installed base. No CISA KEV listing and no public POC code have been identified, reinforcing that this is not currently subject to opportunistic mass exploitation. Even a mid-sized municipal IT team in legnica that operates rsyslogd broadly should first confirm whether imptcp with non-default framing is actually deployed in their environment before escalating incident response resources, since most installations are not vulnerable by default. A critical metadata discrepancy should be noted: the source tags for this CVE include RCE, Information Disclosure, and Privilege Escalation, all of which are explicitly refuted by the CVE description itself - these tags are erroneous and must not be used to inflate severity assessments.
Exploit ScenarioDerived

An attacker with network connectivity to the TCP port on which rsyslogd's imptcp module is listening sends a crafted stream that triggers the oversize-frame recovery logic with a specific input sequence, causing rsyslogd to compute an invalid internal message length and terminate the process. No authentication is required, and the attack requires no user interaction on the target; however, no public POC has been identified. Beyond the immediate loss of the logging daemon, a successful crash may create log gaps that an attacker could exploit to obscure subsequent activity on the system.
This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.4% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Aug 12, 2026

Unauthenticated remote crash of rsyslogd is possible through a flaw in the optional imptcp input module, where a crafted input sequence during oversize-frame recovery produces an invalid internal message length and terminates the logging daemon. Systems running Red Hat Enterprise Linux 6 through 10 are affected only when imptcp is explicitly loaded with a non-default frame delimiting mode; the default imptcp framing and the separate imtcp module are explicitly confirmed unaffected. No public exploit code and no CISA KEV listing have been identified at time of analysis; CVSS scores this at 7.5 High solely on the basis of network-accessible, unauthenticated availability impact.

RemediationAI

No exact patched version number is confirmed in the available intelligence; administrators should verify fix availability directly through the Red Hat security advisory at https://access.redhat.com/security/cve/CVE-2026-19654 and the upstream GitHub advisory at https://github.com/rsyslog/rsyslog/security/advisories/GHSA-cj5r-wh2m-7w29, and apply the vendor-released update when confirmed. As an immediate compensating control with no logging functionality loss for most sites, administrators who do not specifically require imptcp in non-default framing mode should reconfigure rsyslogd to use either imtcp or the default imptcp framing, which eliminates the vulnerable code path entirely. Where non-default imptcp framing is operationally required and patching is delayed, restrict the TCP syslog ingestion port to known trusted source IP ranges via host-based firewall rules (iptables or nftables); this reduces the pool of peers who can trigger the crash but does not eliminate the vulnerability and may not be effective if trusted sources are themselves compromised.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Sign in to check
Technical ContextAI · show details

rsyslogd is the primary system logging daemon shipped with Red Hat Enterprise Linux and many other Linux distributions. The vulnerability resides in the optional imptcp (Input Module for Plain TCP Syslog) plugin, specifically within the oversize-frame recovery code path. CWE-125 (Out-of-bounds Read) indicates the root cause is a memory read operation that extends beyond the valid buffer boundary, producing a corrupted internal message length value that drives rsyslogd to an invalid state and process termination. The flaw is exclusively triggered by non-default TCP frame delimiting modes within imptcp; the standard octet-counting and non-transparent framing defaults do not exercise the vulnerable path. CPE data from Red Hat confirms the affected software surface spans the rsyslog package bundled with RHEL 6, 7, 8, 9, and 10.

Know when Red Hat Enterprise Linux 10 gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources
Continue with Google Continue with GitHub

No credit card · 7-day full trial

Severity by source

Vendor (redhat) PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vuln.today AI 7.5 HIGH

Network-reachable unauthenticated crash with no C/I impact; AC:L because the non-default framing is a server configuration prerequisite, not attacker-side complexity once exposed.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SUSE HIGH
Red Hat 7.5 HIGH

Primary rating from Vendor (redhat).

CVSS VectorVendor: redhat

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

A unauthenticated remote peer may lead rsyslogd to crash due to a flaw in the optional imptcp module. A crafted input sequence during oversize-frame recovery can cause an invalid internal message length and terminate rsyslogd. No confidentiality or integrity impact, privilege escalation, or code execution has been identified. imtcp and the default imptcp framing modes are not affected.

Executive ViewAI

Why It Matters

rsyslogd in Red Hat Enterprise Linux 6-10 contains a vulnerability allowing unauthenticated remote attackers to crash the logging daemon when a specific optional module is configured with non-default settings. This disrupts security event logging and audit trails, creating blind spots in threat detection and compliance monitoring. Organizations using affected RHEL versions must validate their configurations and implement mitigations immediately.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: implement network-based access controls restricting rsyslog listener connections to trusted log sources only; enable automatic service restart policies to reduce logging downtime from crashes; consider switching to imtcp module or reverting to default imptcp frame delimiting as alternative configurations.

Threat Intelligence Overview

EPSS Score
0.4%
Top 67% exploitable
Prevalence
High
default syslog daemon across RHEL and major Linux distributions
Social Media
1
Sightings
Data Quality
8 sources
Confidence: High
EUVD 🇯🇵JVN NVD CVE.org EPSS Vulnrichment MSRC Vendor CIRCL GitHub VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.4%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact
High
Technical Impact
Partial

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Remote Code Execution CRITICAL

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

Affected Products (CPE)CVE.org

cpe:2.3:a:red_hat:red_hat_enterprise_linux_10:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_6:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_6:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_7:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_8:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_9:*:*:*:*:*:*:*:*

More in Red Hat Enterprise Linux 10

View all
CVE-2026-18663 MEDIUM
5.9 Aug 12

Heap corruption via double-free in 389-ds-base's LDAP control parsing allows an unauthenticated remote attacker to crash
CVE-2026-4631 CRITICAL POC
9.8 Apr 07

Remote code execution in Cockpit's web interface allows unauthenticated attackers to execute arbitrary commands on the h
CVE-2026-4480 CRITICAL POC
9.0 May 26

Remote code execution in Samba's printing subsystem allows remote attackers to inject arbitrary shell commands via craft
CVE-2026-101258 HIGH POC
7.8 Oct 06

Ghostscript can execute arbitrary shell commands with the privileges of its process when it renders a crafted PostScript
CVE-2026-96889 HIGH POC
7.8 Sep 23

Use-after-free in librsvg during rendering of crafted SVG documents with nested XInclude directives and duplicate entity
CVE-2026-4775 HIGH POC
7.8 Mar 24

A signed integer overflow vulnerability exists in the libtiff library's putcontig8bitYCbCr44tile function that leads to

CVE-2026-114406 MEDIUM POC
6.8 Oct 21

The system CA trust store shipped in Red Hat's ca-certificates RPM packages includes eMudhra root authorities that signe
CVE-2026-18922 CRITICAL
9.8 Sep 07

Authentication bypass in 389 Directory Server (shipped as Red Hat Directory Server 11-13 and within RHEL 6-10) lets remo
CVE-2026-14544 CRITICAL
9.8 Jul 03

Remote code execution and privilege escalation in HPLIP (HP Linux Imaging and Printing) affects the hpcups print filter

CVE-2026-76578 CRITICAL
9.8 Sep 07

Unauthenticated privilege escalation in FreeIPA (Red Hat Identity Management) allows a remote attacker to gain genuine a
CVE-2026-102560 CRITICAL
9.8 Sep 29

A heap buffer overflow exists in libsoup's WebSocket permessage-deflate compression path: when a very large outbound mes
CVE-2026-5121 HIGH
7.5 Mar 30

Remote code execution in libarchive on 32-bit systems allows unauthenticated attackers to execute arbitrary code via spe

Same weakness CWE-125 – Out-of-bounds Read

View all
CVE-2014-0160 HIGH POC
7.5
CVE-2016-5198 HIGH POC
8.8
CVE-2025-5777 CRITICAL POC
9.3
CVE-2016-1646 HIGH POC
8.8
CVE-2017-5030 HIGH POC
8.8
CVE-2016-4523 HIGH
7.5
CVE-2024-48456 HIGH POC
7.5
CVE-2024-48457 HIGH POC
7.5

Same technique Privilege Escalation

View all
CVE-2024-0012 CRITICAL POC
9.3
CVE-2025-47812 CRITICAL POC
10.0
CVE-2013-0422 CRITICAL POC
9.8
CVE-2013-0632 CRITICAL POC
9.8
CVE-2024-9474 MEDIUM POC
6.9
CVE-2017-5689 CRITICAL POC
9.8
CVE-2021-20021 CRITICAL POC
9.8
CVE-2017-12635 CRITICAL POC
9.8

Vendor StatusVendor

SUSE

Severity: Important
Product Status
SLES15-SP5-CHOST-BYOS-SAP-CCloud Affected
SLES15-SP6-CHOST-BYOS Affected
SLES15-SP6-CHOST-BYOS-Aliyun Affected
SLES15-SP6-CHOST-BYOS-Azure Affected
SLES15-SP6-CHOST-BYOS-EC2 Affected

References

Advisories & patches
ADVISORY https://vuldb.com/vuln/389223 REF https://access.redhat.com/errata/RHSA-2026:66405 REF https://access.redhat.com/errata/RHSA-2026:67583 REF https://access.redhat.com/errata/RHSA-2026:67584 REF https://access.redhat.com/errata/RHSA-2026:71603 REF https://access.redhat.com/errata/RHSA-2026:80817 REF https://access.redhat.com/errata/RHSA-2026:84571 REF https://access.redhat.com/errata/RHSA-2026:84576 REF https://access.redhat.com/errata/RHSA-2026:86124 REF https://access.redhat.com/errata/RHSA-2026:87408 REF https://access.redhat.com/errata/RHSA-2026:91582 REF https://access.redhat.com/security/cve/CVE-2026-19654 REF https://bugzilla.redhat.com/show_bug.cgi?id=2502868 REF https://github.com/rsyslog/rsyslog/security/advisories/GHSA-cj5r-wh2m-7w29

Search Externally

GitHub PoC Exploit-DB PacketStorm Snyk Rapid7 Nuclei Templates Trickest PoC
Back

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