{"id":"CVE-2026-53920","revision":"7a5cbaaf527041bfa1bf40ea0f7e7b85","records":[{"revision":"7a5cbaaf527041bfa1bf40ea0f7e7b85","observedAt":"2026-10-23T16:01:20.601+00:00","statement":{"source":"cve-program","id":"CVE-2026-53920","aliases":[],"title":"odhcpd DHCPv6 Short IA_NA/IA_PD Body Stack Disclosure","description":"odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. From version 17.01.0 to before version 25.12.3, odhcpd's DHCPv6 IA parser accepts an IA_NA or IA_PD option whose body is shorter than struct dhcpv6_ia_hdr, casts the option header to that full structure, and reads ia->iaid before proving that the IA body contains the IAID field. If an unauthenticated network-adjacent client places a zero-length or otherwise short IA option at the end of odhcpd's 8192-byte receive stack buffer, the IAID read crosses from data_buf into adjacent stack memory. The disclosed bytes are then reflected in the DHCPv6 reply IAID; prior ARM validation showed data_buf[8192:8196] disclosing the saved stack canary, and wider stack scans can leak ASLR-useful stack/process contents. This issue has been patched in version 25.12.3.","state":0,"publishedAt":"2026-10-23T13:20:48.045+00:00","modifiedAt":"2026-10-23T13:20:48.045+00:00","affected":[{"ecosystem":"Vendor product","name":"odhcpd","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"openwrt\",\n                    \"product\": \"odhcpd\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 17.01.0, < 25.12.3\",\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:H/VI:N/VA:N/SC:N/SI:N/SA:N","score":8.7,"severity":"HIGH"}],"references":["https://github.com/openwrt/odhcpd/security/advisories/GHSA-p769-5v73-pc4f","https://github.com/openwrt/odhcpd/commit/719fc3abc0d7e7059871f9f572fb05ada86b8ff2","https://github.com/openwrt/odhcpd/commit/f2275efc72a87a95f971f159babcbadc5d241d42"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53920","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53920","identifiers":["CVE-2026-53920"]},"retained":false,"historicalAffected":[]}],"coverage":[]}