{"api_version":"1","generated_at":"2026-08-20T21:21:16+00:00","cve":"CVE-2026-53586","urls":{"html":"https://cve.report/CVE-2026-53586","api":"https://cve.report/api/cve/CVE-2026-53586.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-53586","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-53586"},"summary":{"title":"libgit2: HTTP transport can leak credentials to an offsite redirect target","description":"libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, the built-in HTTP transport in src/libgit2/transports/http.c follows an offsite initial redirect, and handle_remote_auth and handle_auth pass transport->owner->url instead of transport->server.url to the credential callback when the redirected host returns 401 Unauthorized. A callback that scopes credentials to the original trusted URL can therefore return GIT_CREDENTIAL_USERPASS_PLAINTEXT credentials that libgit2 stores in transport->server.cred and sends as an Authorization header to the redirected host. An attacker who controls a trusted Git host or an open redirect on that host can disclose HTTP Basic credentials, personal access tokens, or equivalent credentials. 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This issue is fixed in versions 1.8.6 and 1.9.5."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"HIGH","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-200","description":"CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-522","description":"CWE-522: Insufficiently Protected Credentials","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-601","description":"CWE-601: URL Redirection to Untrusted Site ('Open Redirect')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-20T18:40:08.673Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/libgit2/libgit2/security/advisories/GHSA-2889-x8f6-mc4x","tags":["x_refsource_CONFIRM"],"url":"https://github.com/libgit2/libgit2/security/advisories/GHSA-2889-x8f6-mc4x"},{"name":"https://github.com/libgit2/libgit2/commit/07de6a7e438f95ac9a6efd3222a82117e871ed27","tags":["x_refsource_MISC"],"url":"https://github.com/libgit2/libgit2/commit/07de6a7e438f95ac9a6efd3222a82117e871ed27"},{"name":"https://github.com/libgit2/libgit2/commit/af2b29ad0a74d5bac9751376879ddaf848136d3b","tags":["x_refsource_MISC"],"url":"https://github.com/libgit2/libgit2/commit/af2b29ad0a74d5bac9751376879ddaf848136d3b"},{"name":"https://github.com/libgit2/libgit2/commit/c1507abc44647b3acd832a33a5b1c8c9f5ba8821","tags":["x_refsource_MISC"],"url":"https://github.com/libgit2/libgit2/commit/c1507abc44647b3acd832a33a5b1c8c9f5ba8821"},{"name":"https://github.com/libgit2/libgit2/releases/tag/v1.8.6","tags":["x_refsource_MISC"],"url":"https://github.com/libgit2/libgit2/releases/tag/v1.8.6"},{"name":"https://github.com/libgit2/libgit2/releases/tag/v1.9.5","tags":["x_refsource_MISC"],"url":"https://github.com/libgit2/libgit2/releases/tag/v1.9.5"}],"source":{"advisory":"GHSA-2889-x8f6-mc4x","discovery":"UNKNOWN"},"title":"libgit2: HTTP transport can leak credentials to an offsite redirect target"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-53586","datePublished":"2026-08-20T18:40:08.673Z","dateReserved":"2026-06-09T19:11:53.484Z","dateUpdated":"2026-08-20T18:40:08.673Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-20 19:16:54","lastModifiedDate":"2026-08-20 19:16:54","problem_types":["CWE-200","CWE-522","CWE-601","CWE-200 CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","CWE-522 CWE-522: Insufficiently Protected Credentials","CWE-601 CWE-601: URL Redirection to Untrusted Site ('Open Redirect')"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":2.8,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"53586","Ordinal":"1","Title":"libgit2: HTTP transport can leak credentials to an offsite redir","CVE":"CVE-2026-53586","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"53586","Ordinal":"1","NoteData":"libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, the built-in HTTP transport in src/libgit2/transports/http.c follows an offsite initial redirect, and handle_remote_auth and handle_auth pass transport->owner->url instead of transport->server.url to the credential callback when the redirected host returns 401 Unauthorized. A callback that scopes credentials to the original trusted URL can therefore return GIT_CREDENTIAL_USERPASS_PLAINTEXT credentials that libgit2 stores in transport->server.cred and sends as an Authorization header to the redirected host. An attacker who controls a trusted Git host or an open redirect on that host can disclose HTTP Basic credentials, personal access tokens, or equivalent credentials. This issue is fixed in versions 1.8.6 and 1.9.5.","Type":"Description","Title":"libgit2: HTTP transport can leak credentials to an offsite redir"}]}}}