{"id":"CVE-2026-55490","summary":"OpenWrt: EAD Integer Underflow → Pre-Auth Denial of Service","details":"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.","aliases":["GHSA-9558-77jp-g3fw"],"modified":"2026-07-11T03:54:16.306409687Z","published":"2026-07-07T21:08:26.638Z","database_specific":{"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55490.json","cwe_ids":["CWE-191"]},"references":[{"type":"WEB","url":"https://github.com/openwrt/openwrt/releases/tag/v25.12.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55490.json"},{"type":"ADVISORY","url":"https://github.com/openwrt/openwrt/security/advisories/GHSA-9558-77jp-g3fw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55490"},{"type":"FIX","url":"https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openwrt/openwrt","events":[{"introduced":"0"},{"fixed":"f0a60eee2fe051741c643ea6118718aae1ef17fb"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"25.12.5"}],"source":"AFFECTED_FIELD"}}],"versions":["v25.12.4","v25.12.3","v25.12.2","v25.12.1","v25.12.0","v25.12.0-rc5","v25.12.0-rc4","v25.12.0-rc3","v25.12.0-rc2","v25.12.0-rc1","reboot"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55490.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}