{"id":"CVE-2026-55490","state":"PUBLISHED","title":"OpenWrt: EAD Integer Underflow → Pre-Auth Denial of Service","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.","publishedAt":"2026-07-07T21:08:26.638Z","updatedAt":"2026-07-08T13:52:07.490Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["openwrt openwrt"],"affected":[{"vendor":"openwrt","product":"openwrt","versions":[{"version":"< 25.12.5","status":"affected"}]}],"references":["https://github.com/openwrt/openwrt/security/advisories/GHSA-9558-77jp-g3fw","https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5","https://github.com/openwrt/openwrt/releases/tag/v25.12.5"],"weaknesses":["CWE-191"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55490.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55490","state":"PUBLISHED","datePublished":"2026-07-07T21:08:26.638Z","dateUpdated":"2026-07-08T13:52:07.490Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T22:28:27.062Z"},"containers":{"cna":{"title":"OpenWrt: EAD Integer Underflow → Pre-Auth Denial of Service","descriptions":[{"lang":"en","value":"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":[{"vendor":"openwrt","product":"openwrt","versions":[{"version":"< 25.12.5","status":"affected"}]}],"references":[{"url":"https://github.com/openwrt/openwrt/security/advisories/GHSA-9558-77jp-g3fw","name":"https://github.com/openwrt/openwrt/security/advisories/GHSA-9558-77jp-g3fw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5","name":"https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08ca5","tags":["x_refsource_MISC"]},{"url":"https://github.com/openwrt/openwrt/releases/tag/v25.12.5","name":"https://github.com/openwrt/openwrt/releases/tag/v25.12.5","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"ADJACENT_NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-191","lang":"en","description":"CWE-191: Integer Underflow (Wrap or Wraparound)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-07T21:08:26.638Z"},"source":{"advisory":"GHSA-9558-77jp-g3fw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-08T13:51:49.570163Z","id":"CVE-2026-55490","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-08T13:52:07.490Z"}}]}}}