{"id":"CVE-2026-30872","state":"PUBLISHED","title":"OpenWrt Project has a Stack-based Buffer Overflow vulnerability via IPv6 reverse DNS lookup","description":"OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the match_ipv6_addresses function, triggered when processing PTR queries for IPv6 reverse DNS domains (.ip6.arpa) received via multicast DNS on UDP port 5353. During processing, the domain name from name_buffer is copied via strcpy into a fixed 256-byte stack buffer, and then the reverse IPv6 request is extracted into a buffer of only 46 bytes (INET6_ADDRSTRLEN). Because the length of the data is never validated before this extraction, an attacker can supply input larger than 46 bytes, causing an out-of-bounds write. This allows a specially crafted DNS query to overflow the stack buffer in match_ipv6_addresses, potentially enabling remote code execution. This issue has been fixed in versions 24.10.6 and 25.12.1.","publishedAt":"2026-03-19T21:56:23.472Z","updatedAt":"2026-03-25T03:56:13.660Z","severity":{"score":9.5,"label":"Critical","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["openwrt openwrt"],"affected":[{"vendor":"openwrt","product":"openwrt","versions":[{"version":">= 25.12.0-rc1, < 25.12.1","status":"affected"},{"version":"< 24.10.6","status":"affected"}]}],"references":["https://github.com/openwrt/openwrt/security/advisories/GHSA-mpgh-v658-jqv5","https://github.com/openwrt/openwrt/releases/tag/v24.10.6","https://github.com/openwrt/openwrt/releases/tag/v25.12.1"],"weaknesses":["CWE-121"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/30xxx/CVE-2026-30872.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-30872","state":"PUBLISHED","datePublished":"2026-03-19T21:56:23.472Z","dateUpdated":"2026-03-25T03:56:13.660Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-06T00:04:56.698Z"},"containers":{"cna":{"title":"OpenWrt Project has a Stack-based Buffer Overflow vulnerability via IPv6 reverse DNS lookup","descriptions":[{"lang":"en","value":"OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the match_ipv6_addresses function, triggered when processing PTR queries for IPv6 reverse DNS domains (.ip6.arpa) received via multicast DNS on UDP port 5353. During processing, the domain name from name_buffer is copied via strcpy into a fixed 256-byte stack buffer, and then the reverse IPv6 request is extracted into a buffer of only 46 bytes (INET6_ADDRSTRLEN). Because the length of the data is never validated before this extraction, an attacker can supply input larger than 46 bytes, causing an out-of-bounds write. This allows a specially crafted DNS query to overflow the stack buffer in match_ipv6_addresses, potentially enabling remote code execution. This issue has been fixed in versions 24.10.6 and 25.12.1."}],"affected":[{"vendor":"openwrt","product":"openwrt","versions":[{"version":">= 25.12.0-rc1, < 25.12.1","status":"affected"},{"version":"< 24.10.6","status":"affected"}]}],"references":[{"url":"https://github.com/openwrt/openwrt/security/advisories/GHSA-mpgh-v658-jqv5","name":"https://github.com/openwrt/openwrt/security/advisories/GHSA-mpgh-v658-jqv5","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/openwrt/openwrt/releases/tag/v24.10.6","name":"https://github.com/openwrt/openwrt/releases/tag/v24.10.6","tags":["x_refsource_MISC"]},{"url":"https://github.com/openwrt/openwrt/releases/tag/v25.12.1","name":"https://github.com/openwrt/openwrt/releases/tag/v25.12.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"HIGH","baseScore":9.5,"baseSeverity":"CRITICAL","vectorString":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-121","lang":"en","description":"CWE-121: Stack-based Buffer Overflow","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-19T21:56:23.472Z"},"source":{"advisory":"GHSA-mpgh-v658-jqv5","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-24T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-30872"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-25T03:56:13.660Z"}}]}}}