{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-45123", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-05-08T20:08:17.208Z", "datePublished": "2026-08-18T15:44:26.555Z", "dateUpdated": "2026-08-18T15:44:26.555Z"}, "containers": {"cna": {"title": "MyBB: IPv6 SSRF", "problemTypes": [{"descriptions": [{"cweId": "CWE-918", "lang": "en", "description": "CWE-918: Server-Side Request Forgery (SSRF)", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/mybb/mybb/security/advisories/GHSA-56wr-64wx-5g7j", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/mybb/mybb/security/advisories/GHSA-56wr-64wx-5g7j"}, {"name": "https://github.com/mybb/mybb/commit/9cdadbf66f4cef50019f13aaa8e3470ea6535cb7", "tags": ["x_refsource_MISC"], "url": "https://github.com/mybb/mybb/commit/9cdadbf66f4cef50019f13aaa8e3470ea6535cb7"}, {"name": "https://github.com/mybb/mybb/releases/tag/mybb_1840", "tags": ["x_refsource_MISC"], "url": "https://github.com/mybb/mybb/releases/tag/mybb_1840"}, {"name": "https://mybb.com/versions/1.8.40", "tags": ["x_refsource_MISC"], "url": "https://mybb.com/versions/1.8.40"}], "affected": [{"vendor": "mybb", "product": "mybb", "versions": [{"version": "< 1.8.40", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-18T15:44:26.555Z"}, "descriptions": [{"lang": "en", "value": "MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetch_remote_file() fails open when get_ip_by_hostname() returns no result because that function does not return IPv6 results, allowing a crafted remote target to bypass the host restriction. The uniquely identifying implementation details include fail-open verification, and inc/functions.php. This issue is fixed in version 1.8.40."}], "source": {"advisory": "GHSA-56wr-64wx-5g7j", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "mybb", "vendor": "mybb", "versions": [{"status": "affected", "version": "< 1.8.40"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetch_remote_file() fails open when get_ip_by_hostname() returns no result because that function does not return IPv6 results, allowing a crafted remote target to bypass the host restriction. The uniquely identifying implementation details include fail-open verification, and inc/functions.php. This issue is fixed in version 1.8.40."}], "id": "CVE-2026-45123", "lastModified": "2026-08-18T16:17:07.383", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-08-18T16:17:07.383", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/mybb/mybb/commit/9cdadbf66f4cef50019f13aaa8e3470ea6535cb7"}, {"source": "security-advisories@github.com", "url": "https://github.com/mybb/mybb/releases/tag/mybb_1840"}, {"source": "security-advisories@github.com", "url": "https://github.com/mybb/mybb/security/advisories/GHSA-56wr-64wx-5g7j"}, {"source": "security-advisories@github.com", "url": "https://mybb.com/versions/1.8.40"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-918"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.8.40)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "mybb", "source": "cna", "vendor": "mybb"}, "product": "mybb", "vendor": "mybb"}], "created": "2026-08-18T17:30:15.394616+00:00", "updated": "2026-08-18T17:30:15.394635+00:00", "vendors": ["mybb", "mybb$PRODUCT$mybb"]}