--- cve: "CVE-2026-53586" severity: "MEDIUM" cvss: 6.5 epss: "0.3%" vendor: "libgit2" kev: false exploited: false published: "2026-08-20 19:16:54" tags: [cve, security, medium] source: tsecurity.de CVE-Dossier exported: "2026-09-21T12:20:16+02:00" --- # CVE-2026-53586 > 6.5 MEDIUM · 🧪 PoC ## Beschreibung 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. ## CVSS-Vektor ``` CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N ``` | Metrik | Wert | Bewertung | |---|---|---| | AV Angriffsvektor | Netzwerk | bad | | AC Komplexität | Gering | bad | | PR Privilegien | Keine | bad | | UI Interaktion | Erforderlich | good | | S Scope | Unverändert | good | | C Vertraulichkeit | Hoch | bad | | I Integrität | Keine | good | | A Verfügbarkeit | Keine | good | ## Patch verfügbar (OSV) - 5853918c4c6a7b12f8becf4bd11ff4362ebb9020 (Commit) - f7a4071c766ceea3915415e22134cbe3e581c420 (Commit) ## Referenzen - - - - - - --- _Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53586) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_