What is CVE-2026-55490?

CVE-2026-55490 is a medium-severity vulnerability in Openwrt, classified under Integer Underflow. CVSS score: 6.5/10. Published 2026-07-07.

How severe is CVE-2026-55490?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Integer overflow in Openwrt

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 network to crash the daemon by sending…

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Openwrt — versions < 25.12.5

Weakness classification (CWE)

CWE-191 — Integer Underflow

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-55490?: CVE-2026-55490 is a medium-severity vulnerability in Openwrt, classified under Integer Underflow. CVSS score: 6.5/10. Published 2026-07-07.
How severe is CVE-2026-55490?: Medium severity. CVSS v3 base score is 6.5 out of 10.