CVE-2026-45115

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-45115", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-05-08T20:08:17.207Z", "datePublished": "2026-08-18T15:46:00.862Z", "dateUpdated": "2026-08-18T17:55:22.351Z"}, "containers": {"cna": {"title": "MyBB: Buddy/ignore list username XSS", "problemTypes": [{"descriptions": [{"cweId": "CWE-79", "lang": "en", "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/mybb/mybb/security/advisories/GHSA-p766-qqxv-rfc2", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/mybb/mybb/security/advisories/GHSA-p766-qqxv-rfc2"}, {"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": "2026-08-18T15:46:00.862Z"}, "descriptions": [{"lang": "en", "value": "MyBB is free and open source forum software. Prior to 1.8.40, the Buddy/Ignore component does not sanitize usernames correctly, allowing attackers to perform JavaScript code injection through a specially crafted username. The User CP Buddy/Ignore list and the Select Buddies list in Private Messages pass usernames through htmlspecialchars_uni(), which may leave single quotes unescaped. The payload is triggered when a victim chooses Yes in Please Confirm while removing the username in usercp.php, or selects the username through the onclick handler in the xmlhttp.php Select Buddies popup. The uniquely identifying implementation details include Private Messages Select Buddies list, and unescaped single quotes. This issue is fixed in version 1.8.40."}], "source": {"advisory": "GHSA-p766-qqxv-rfc2", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-18T17:55:15.036117Z", "id": "CVE-2026-45115", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-18T17:55:22.351Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-45115", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-08-18T17:55:15.036117Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-18T17:55:18.854Z"}}], "cna": {"title": "MyBB: Buddy/ignore list username XSS", "source": {"advisory": "GHSA-p766-qqxv-rfc2", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.7, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}], "affected": [{"vendor": "mybb", "product": "mybb", "versions": [{"status": "affected", "version": "< 1.8.40"}]}], "references": [{"url": "https://github.com/mybb/mybb/security/advisories/GHSA-p766-qqxv-rfc2", "name": "https://github.com/mybb/mybb/security/advisories/GHSA-p766-qqxv-rfc2", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/mybb/mybb/releases/tag/mybb_1840", "name": "https://github.com/mybb/mybb/releases/tag/mybb_1840", "tags": ["x_refsource_MISC"]}, {"url": "https://mybb.com/versions/1.8.40", "name": "https://mybb.com/versions/1.8.40", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "MyBB is free and open source forum software. Prior to 1.8.40, the Buddy/Ignore component does not sanitize usernames correctly, allowing attackers to perform JavaScript code injection through a specially crafted username. The User CP Buddy/Ignore list and the Select Buddies list in Private Messages pass usernames through htmlspecialchars_uni(), which may leave single quotes unescaped. The payload is triggered when a victim chooses Yes in Please Confirm while removing the username in usercp.php, or selects the username through the onclick handler in the xmlhttp.php Select Buddies popup. The uniquely identifying implementation details include Private Messages Select Buddies list, and unescaped single quotes. This issue is fixed in version 1.8.40."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-79", "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-18T15:46:00.862Z"}}}, "cveMetadata": {"cveId": "CVE-2026-45115", "state": "PUBLISHED", "dateUpdated": "2026-08-18T17:55:22.351Z", "dateReserved": "2026-05-08T20:08:17.207Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-08-18T15:46:00.862Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"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 Buddy/Ignore component does not sanitize usernames correctly, allowing attackers to perform JavaScript code injection through a specially crafted username. The User CP Buddy/Ignore list and the Select Buddies list in Private Messages pass usernames through htmlspecialchars_uni(), which may leave single quotes unescaped. The payload is triggered when a victim chooses Yes in Please Confirm while removing the username in usercp.php, or selects the username through the onclick handler in the xmlhttp.php Select Buddies popup. The uniquely identifying implementation details include Private Messages Select Buddies list, and unescaped single quotes. This issue is fixed in version 1.8.40."}], "id": "CVE-2026-45115", "lastModified": "2026-09-08T21:02:26.047", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.3, "impactScore": 5.8, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-45115", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-18T17:55:15.036117Z", "version": "2.0.3"}}]}, "published": "2026-08-18T16:17:06.180", "references": [{"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-p766-qqxv-rfc2"}, {"source": "security-advisories@github.com", "url": "https://mybb.com/versions/1.8.40"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"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": "2026-08-18T17:30:15.394306+00:00", "updated": "2026-08-18T18:00:04.559911+00:00", "vendors": ["mybb", "mybb$PRODUCT$mybb"]}