{"id":"CVE-2026-53918","revision":"ba26b42074fc4738b4eed00f1afe12dd","records":[{"revision":"ba26b42074fc4738b4eed00f1afe12dd","observedAt":"2026-10-23T16:01:20.601+00:00","statement":{"source":"cve-program","id":"CVE-2026-53918","aliases":[],"title":"odhcpd DHCPv6 IA dangling first pointer use-after-free","description":"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.","state":0,"publishedAt":"2026-10-23T13:21:00.665+00:00","modifiedAt":"2026-10-23T13:21:00.665+00:00","affected":[{"ecosystem":"Vendor product","name":"odhcpd","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"openwrt\",\n                    \"product\": \"odhcpd\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 25.12\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","score":8.8,"severity":"HIGH"}],"references":["https://github.com/openwrt/odhcpd/security/advisories/GHSA-44ff-jcwh-wgc2","https://github.com/openwrt/odhcpd/commit/26b122007030ebf192376aff8f98d428b25e2a93","https://github.com/openwrt/odhcpd/commit/5b283832c0a77aed20f1cc384ffc40bc768b06e9"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53918","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53918","identifiers":["CVE-2026-53918"]},"retained":false,"historicalAffected":[]}],"coverage":[]}