1. Home
  2. CVE Database
  3. CVE-2026-55490
MEDIUM · 6.5

CVE-2026-55490

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...

Vulnerability Description

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.

CVSS Score

6.5

MEDIUM

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
ADJACENT_NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH

Affected Products

VendorProductVersions
OpenwrtOpenwrt< 25.12.5

Related Weaknesses (CWE)

CWE-191

References

FAQ

What is CVE-2026-55490?

CVE-2026-55490 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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...

How severe is CVE-2026-55490?

CVE-2026-55490 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-55490?

Check the references section above for vendor advisories and patch information. Affected products include: Openwrt Openwrt.