CVE-2026-55490
Published:July 07, 2026
Updated:August 04, 2026
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.
Affected Packages
https://github.com/openwrt/openwrt.git (GITHUB):
Affected version(s) >=v17.01.0-rc1 <v25.12.5Fix Suggestion:
Update to version v25.12.5Related Resources (5)
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Contact UsCVSS v4
Base Score:
7.1
Attack Vector
ADJACENT
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Integer Underflow (Wrap or Wraparound)
EPSS
Base Score:
0.99