{"schema":"threatline.record/2","record":{"id":"CVE-2026-53918","aliases":["GHSA-44ff-jcwh-wgc2"],"summary":"odhcpd DHCPv6 IA dangling first pointer use-after-free","details":"odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. Prior to version 25.12, odhcpd's DHCPv6 IA handler keeps a per-message `first` lease pointer so multiple IA options in one message reuse the same Reconfigure authentication key. A DHCPv6 REQUEST from an adjacent-network client can make the first IA set `first`, then make a later same-IAID IA fail the on-link check and free that same lease, leaving `first` dangling. A following IA in the same packet allocates a new lease and copies `first->key`, producing a 16-byte heap-use-after-free read. ASan confirms the UAF; native tracing shows the packet shape can deterministically reclaim the freed lease as the destination allocation, producing a zeroed Reconfigure key copy. The validated impact is unauthenticated adjacent-network denial of service and DHCPv6 Reconfigure/ForceRenew key confusion. Arbitrary PC control is not proven for this UAF alone. This issue has been patched in version 25.12.","categories":["Network & edge"],"product":"odhcpd","vendor":"openwrt","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-53918","source_modified_at":"2026-10-23T13:21:00.665Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"odhcpd","vendor":"openwrt","versions":[{"version":"< 25.12","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":8.8,"severity":"High","kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-23T13:21:00.665Z","modified_at":"2026-10-23T13:21:00.665Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-53918","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T13:21:00.665Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://github.com/openwrt/odhcpd/security/advisories/GHSA-44ff-jcwh-wgc2","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/openwrt/odhcpd/commit/26b122007030ebf192376aff8f98d428b25e2a93","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/openwrt/odhcpd/commit/5b283832c0a77aed20f1cc384ffc40bc768b06e9","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"vendor and product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-23T13:21:00.665Z","content_hash":"f4ccad29b6dd9a4aed47b6a391c3b3826a21dd93114abc34e7bb69f0c40b173e"}}