{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53918", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-11T15:46:12.315Z", "datePublished": "2026-10-23T13:21:00.665Z", "dateUpdated": "2026-10-30T17:42:21.816Z" }, "containers": { "cna": { "title": "odhcpd DHCPv6 IA dangling first pointer use-after-free", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-416", "lang": "en", "description": "CWE-416: Use After Free", "type": "CWE" } ] }, { "descriptions": [ { "cweId": "CWE-672", "lang": "en", "description": "CWE-672: Operation on a Resource after Expiration or Release", "type": "CWE" } ] }, { "descriptions": [ { "cweId": "CWE-825", "lang": "en", "description": "CWE-825: Expired Pointer Dereference", "type": "CWE" } ] } ], "metrics": [ { "cvssV4_0": { "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.8, "baseSeverity": "HIGH", "vectorString": "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", "version": "4.0" } } ], "references": [ { "name": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-44ff-jcwh-wgc2", "tags": [ "x_refsource_CONFIRM" ], "url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-44ff-jcwh-wgc2" }, { "name": "https://github.com/openwrt/odhcpd/commit/26b122007030ebf192376aff8f98d428b25e2a93", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/openwrt/odhcpd/commit/26b122007030ebf192376aff8f98d428b25e2a93" }, { "name": "https://github.com/openwrt/odhcpd/commit/5b283832c0a77aed20f1cc384ffc40bc768b06e9", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/openwrt/odhcpd/commit/5b283832c0a77aed20f1cc384ffc40bc768b06e9" } ], "affected": [ { "vendor": "openwrt", "product": "odhcpd", "versions": [ { "version": "< 25.12", "status": "affected" } ] } ], "providerMetadata": { "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-23T13:21:00.665Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "source": { "advisory": "GHSA-44ff-jcwh-wgc2", "discovery": "UNKNOWN" } }, "adp": [ { "references": [ { "url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-44ff-jcwh-wgc2", "tags": [ "exploit" ] } ], "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-10-30T17:42:15.930203Z", "id": "CVE-2026-53918", "options": [ { "Exploitation": "poc" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-30T17:42:21.816Z" } } ] } }