{"data":{"id":"b3a9b9d7-5a1f-4687-9b83-be0e1e75120b","title":"CVE-2026-31951: LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc1 through 0.8.3-rc1, user-created MCP (Model…","summary":"CVE-2026-31951 affects LibreChat versions 0.8.2-rc1 through 0.8.3-rc1. User-created MCP (Model Context Protocol) servers can set arbitrary HTTP headers that undergo credential placeholder substitution, so a malicious server using `{{LIBRECHAT_OPENID_ACCESS_TOKEN}}` in its headers can exfiltrate the OAuth tokens of users who call tools on that server. The weakness is classified as CWE-200, Exposure of Sensitive Information to an Unauthorized Actor.","solution":"Fixed in 0.8.3-rc2.","labels":["security"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-31951","publishedAt":"2026-03-27T20:16:30.397Z","cveId":"CVE-2026-31951","cweIds":["CWE-200"],"cvssScore":"6.8","cvssSeverity":"medium","severity":"medium","attackType":["other"],"issueType":"vulnerability","affectedPackages":null,"affectedPackageNames":null,"affectedPackageRefs":null,"affectedVendors":[],"affectedVendorsRaw":["LibreChat"],"classifierModel":"claude-haiku-5-5","classifierPromptVersion":"v4","summaryPromptVersion":"v2","headline":"LibreChat OAuth token exfiltration through user-created MCP server headers","headlinePromptVersion":"h1","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N","attackVector":"network","attackComplexity":"low","privilegesRequired":"low","userInteraction":"required","exploitMaturity":"unknown","epssScore":0.00253,"epssCheckedAt":"2026-11-10T00:11:22.478Z","kevDateAdded":null,"advisoryAliases":null,"affectedPackagesSource":null,"affectedPackagesCheckedAt":"2026-11-03T18:10:49.415Z","patchAvailable":null,"disclosureDate":"2026-03-27T20:16:30.397Z","fixReleasedAt":null,"daysToFix":null,"fixCheckedAt":null,"capecIds":["CAPEC-116"],"crossRefCount":0,"attackSophistication":"moderate","impactType":["confidentiality"],"aiComponentTargeted":"plugin","llmSpecific":true,"classifierConfidence":0.9,"researchCategory":null,"atlasIds":null,"fixes":[]}}