{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-18526", "assignerOrgId": "84fe0718-d6bb-4716-a7e8-81a6d1daa869", "state": "PUBLISHED", "assignerShortName": "Fluid Attacks", "dateReserved": "2026-07-31T19:46:36.482Z", "datePublished": "2026-08-19T14:17:00.896Z", "dateUpdated": "2026-08-19T14:17:00.896Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "platforms": ["Windows", "MacOS", "Linux"], "product": "HumHub", "repo": "https://github.com/humhub/humhub", "vendor": "HumHub", "versions": [{"status": "affected", "version": "1.18.4"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:humhub:humhub:1.18.4:*:windows:*:*:*:*:*", "vulnerable": true}, {"criteria": "cpe:2.3:a:humhub:humhub:1.18.4:*:macos:*:*:*:*:*", "vulnerable": true}, {"criteria": "cpe:2.3:a:humhub:humhub:1.18.4:*:linux:*:*:*:*:*", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "OR"}], "credits": [{"lang": "en", "type": "finder", "value": "Miguel Gomez"}, {"lang": "en", "type": "finder", "value": "Fluid Attacks' AI SAST Scanner"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<span style=\"background-color: rgb(255, 255, 255);\">HumHub Community Edition 1.18.4 and 1.18.4-pl1 contain a stored Cross-Site Scripting (XSS) vulnerability in the oEmbed confirmation rendering workflow.</span><br>"}], "value": "HumHub Community Edition 1.18.4 and 1.18.4-pl1 contain a stored Cross-Site Scripting (XSS) vulnerability in the oEmbed confirmation rendering workflow."}], "impacts": [{"capecId": "CAPEC-63", "descriptions": [{"lang": "en", "value": "CAPEC-63 Cross-Site Scripting (XSS)"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 7.4, "baseSeverity": "HIGH", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-79", "description": "CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "84fe0718-d6bb-4716-a7e8-81a6d1daa869", "shortName": "Fluid Attacks", "dateUpdated": "2026-08-19T14:17:00.896Z"}, "references": [{"tags": ["third-party-advisory"], "url": "https://fluidattacks.com/advisories/greeicy"}, {"tags": ["product"], "url": "https://github.com/humhub/humhub"}, {"tags": ["patch"], "url": "https://github.com/humhub/humhub/pull/8373"}], "source": {"discovery": "UNKNOWN"}, "title": "HumHub 1.18.4 / 1.18.4-pl1 \u2013 Stored Cross-Site Scripting in oEmbed confirmation", "x_generator": {"engine": "Vulnogram 0.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "platforms": ["Windows", "MacOS", "Linux"], "product": "HumHub", "repo": "https://github.com/humhub/humhub", "vendor": "HumHub", "versions": [{"status": "affected", "version": "1.18.4"}]}], "source": "help@fluidattacks.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "HumHub Community Edition 1.18.4 and 1.18.4-pl1 contain a stored Cross-Site Scripting (XSS) vulnerability in the oEmbed confirmation rendering workflow."}], "id": "CVE-2026-18526", "lastModified": "2026-08-19T15:16:58.010", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "help@fluidattacks.com", "type": "Secondary"}]}, "published": "2026-08-19T15:16:58.010", "references": [{"source": "help@fluidattacks.com", "url": "https://fluidattacks.com/advisories/greeicy"}, {"source": "help@fluidattacks.com", "url": "https://github.com/humhub/humhub"}, {"source": "help@fluidattacks.com", "url": "https://github.com/humhub/humhub/pull/8373"}], "sourceIdentifier": "help@fluidattacks.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "help@fluidattacks.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": ["windows", "macos", "linux"], "status": "affected", "versions": {"scheme": "semver", "value": "1.18.4"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "HumHub", "source": "cna", "vendor": "HumHub"}, "product": "humhub", "vendor": "humhub"}], "created": "2026-08-19T16:45:03.166906+00:00", "updated": "2026-08-19T17:45:03.230442+00:00", "vendors": ["humhub", "humhub$PRODUCT$humhub"]}