CVE-2026-55490: Openwrt

Medium severity, CVSS 6.5. EPSS: 0.7% chance of exploitation in the next 30 days.

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 products

• Openwrt Openwrt: before 25.12.5 (fixed in 25.12.5)

Published 2026-07-07. Last modified 2026-07-10.