CVE-2026-55606

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-55606", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-16T23:31:22.445Z", "datePublished": "2026-10-23T13:21:21.038Z", "dateUpdated": "2026-10-29T17:43:41.478Z"}, "containers": {"cna": {"title": "odhcpd: Stack buffer overread via DUID length endianness mismatch in memcmp()", "problemTypes": [{"descriptions": [{"cweId": "CWE-126", "lang": "en", "description": "CWE-126: Buffer Over-read", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L", "version": "3.1"}}], "references": [{"name": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45"}, {"name": "https://github.com/openwrt/odhcpd/pull/401", "tags": ["x_refsource_MISC"], "url": "https://github.com/openwrt/odhcpd/pull/401"}, {"name": "https://github.com/openwrt/odhcpd/commit/6907f28f9ddeef9f69f5ee10bbc9ba8adc0ef57f", "tags": ["x_refsource_MISC"], "url": "https://github.com/openwrt/odhcpd/commit/6907f28f9ddeef9f69f5ee10bbc9ba8adc0ef57f"}, {"name": "https://github.com/openwrt/odhcpd/commit/ed38cffa927d5fd450d20bfd3f7fb8d8e8fff301", "tags": ["x_refsource_MISC"], "url": "https://github.com/openwrt/odhcpd/commit/ed38cffa927d5fd450d20bfd3f7fb8d8e8fff301"}], "affected": [{"vendor": "openwrt", "product": "odhcpd", "versions": [{"version": "<= 25.12", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-23T13:21:21.038Z"}, "descriptions": [{"lang": "en", "value": "odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In versions 25.12 and prior, odhcpd's DHCPv6 self-loop detection at dhcpv6.c:720 uses a network-byte-order DUID length value directly as the memcmp() size parameter. On little-endian hosts, this causes memcmp() to read far beyond the stack buffer \u2014 a single unauthenticated DHCPv6 packet triggers a 2560-byte overread from a 128-byte buffer. At time of publication, there are no publicly available patches."}], "source": {"advisory": "GHSA-x8x4-7gvf-gp45", "discovery": "UNKNOWN"}}, "adp": [{"references": [{"url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-10-29T17:43:15.504706Z", "id": "CVE-2026-55606", "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": "2026-10-29T17:43:41.478Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-55606", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-29T17:43:15.504706Z"}}}], "references": [{"url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-29T17:43:34.971Z"}}], "cna": {"title": "odhcpd: Stack buffer overread via DUID length endianness mismatch in memcmp()", "source": {"advisory": "GHSA-x8x4-7gvf-gp45", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}}], "affected": [{"vendor": "openwrt", "product": "odhcpd", "versions": [{"status": "affected", "version": "<= 25.12"}]}], "references": [{"url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45", "name": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/openwrt/odhcpd/pull/401", "name": "https://github.com/openwrt/odhcpd/pull/401", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/openwrt/odhcpd/commit/6907f28f9ddeef9f69f5ee10bbc9ba8adc0ef57f", "name": "https://github.com/openwrt/odhcpd/commit/6907f28f9ddeef9f69f5ee10bbc9ba8adc0ef57f", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/openwrt/odhcpd/commit/ed38cffa927d5fd450d20bfd3f7fb8d8e8fff301", "name": "https://github.com/openwrt/odhcpd/commit/ed38cffa927d5fd450d20bfd3f7fb8d8e8fff301", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In versions 25.12 and prior, odhcpd's DHCPv6 self-loop detection at dhcpv6.c:720 uses a network-byte-order DUID length value directly as the memcmp() size parameter. On little-endian hosts, this causes memcmp() to read far beyond the stack buffer \u2014 a single unauthenticated DHCPv6 packet triggers a 2560-byte overread from a 128-byte buffer. At time of publication, there are no publicly available patches."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-126", "description": "CWE-126: Buffer Over-read"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-23T13:21:21.038Z"}}}, "cveMetadata": {"cveId": "CVE-2026-55606", "state": "PUBLISHED", "dateUpdated": "2026-10-29T17:43:41.478Z", "dateReserved": "2026-06-16T23:31:22.445Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-10-23T13:21:21.038Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "odhcpd", "vendor": "openwrt", "versions": [{"status": "affected", "version": "<= 25.12"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In versions 25.12 and prior, odhcpd's DHCPv6 self-loop detection at dhcpv6.c:720 uses a network-byte-order DUID length value directly as the memcmp() size parameter. On little-endian hosts, this causes memcmp() to read far beyond the stack buffer \u2014 a single unauthenticated DHCPv6 packet triggers a 2560-byte overread from a 128-byte buffer. At time of publication, there are no publicly available patches."}], "id": "CVE-2026-55606", "lastModified": "2026-10-29T18:17:33.527", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 2.5, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55606", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-29T17:43:15.504706Z", "version": "2.0.3"}}]}, "published": "2026-10-23T14:17:53.850", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/openwrt/odhcpd/commit/6907f28f9ddeef9f69f5ee10bbc9ba8adc0ef57f"}, {"source": "security-advisories@github.com", "url": "https://github.com/openwrt/odhcpd/commit/ed38cffa927d5fd450d20bfd3f7fb8d8e8fff301"}, {"source": "security-advisories@github.com", "url": "https://github.com/openwrt/odhcpd/pull/401"}, {"source": "security-advisories@github.com", "url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-126"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,25.12]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "odhcpd", "source": "cna", "vendor": "openwrt"}, "product": "odhcpd", "vendor": "openwrt"}], "created": "2026-10-23T16:30:18.694464+00:00", "updated": "2026-10-23T23:30:17.460770+00:00", "vendors": ["openwrt", "openwrt$PRODUCT$odhcpd"]}