CVE-2026-55490
Medium
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.
SeverityMedium
CVSS6.5
Exploit probability—
ProductOpenwrt
PublishedJul 7, 2026
First seenJul 7, 2026
Weakness typeCWE-191CWE-191
How to fix
Update
- openwrt openwrt25.12.5 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| openwrt openwrt | v < 25.12.5 | 25.12.5 |
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