What is the CVSS score of EUVD-2026-42110?

EUVD-2026-42110 has a CVSS 3.1 base score of 6.5 (Medium). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.6%.

Is there a patch available for EUVD-2026-42110?

Yes, a patch is available for EUVD-2026-42110. Update the affected software to the latest version immediately.

OpenWrt EUVD-2026-42110

| CVE-2026-55490 MEDIUM

Integer Underflow (CWE-191)

2026-07-07 GitHub_M

Integer Overflow Denial Of Service Openwrt

6.5

CVSS 3.1 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

6.5 MEDIUM

AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

vuln.today AI

6.5 MEDIUM

AV:A because exploitation requires local network adjacency; PR:N and AC:L since a single unauthenticated UDP packet suffices; A:H for daemon crash; C:N/I:N as no data is accessed or modified.

3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

4.0 AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Patch available

Jul 07, 2026 - 23:01 EUVD

Analysis Generated

Jul 07, 2026 - 22:09 vuln.today

CVE Published

Jul 07, 2026 - 21:08 cve.org

MEDIUM 6.5

DescriptionCVE.org

OpenWrt is a Linux operating system targeting embedded devices. Before v25.12.5, an integer underflow in handle_send_a() of the Emergency Access Daemon allows any unauthenticated attacker on the local network to crash the daemon by sending a single crafted UDP packet. The message length underflows before a bounds check and is then passed to memcpy as a very large size. This issue is fixed v25.12.5.

AnalysisAI

Integer underflow in the OpenWrt Emergency Access Daemon crashes the daemon when any unauthenticated attacker on the local network sends a single crafted UDP packet to it. Affected are all OpenWrt versions prior to v25.12.5. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access

Gain adjacent network access (LAN/Wi-Fi)

Delivery

identify OpenWrt device running EAD

Exploit

craft UDP packet with underflowing length field

Execution

send single packet to EAD listening port

Persist

integer underflow passed to memcpy

Impact

daemon crash, EAD unavailable

Access

Gain adjacent network access (LAN/Wi-Fi)

Delivery

identify OpenWrt device running EAD

Exploit

craft UDP packet with underflowing length field

Execution

send single packet to EAD listening port

Persist

integer underflow passed to memcpy

Impact

daemon crash, EAD unavailable

Vulnerability AssessmentAI

Exploitation	The Emergency Access Daemon must be running and reachable on the target device (its default operational state on affected OpenWrt versions). … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	The NVD CVSS 3.1 base score of 6.5 (Medium) accurately reflects the constrained impact profile. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An attacker positioned on the same local network segment as an unpatched OpenWrt device constructs a UDP packet with a message length field set so that the subtraction in handle_send_a() wraps to a very large unsigned integer. The attacker sends this single packet to the Emergency Access Daemon's listening UDP port; the daemon passes the underflowed length to memcpy, triggering a crash and making EAD unavailable. …
Remediation	Upgrade to OpenWrt v25.12.5, which contains the confirmed fix per the upstream release at https://github.com/openwrt/openwrt/releases/tag/v25.12.5 and the patch commit at https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5. … Detailed patch versions, workarounds, and compensating controls in full report.