{"apiVersion":"1.0","identifier":"CVE-2026-53583","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, verify_server_cert in src/libgit2/streams/openssl.c uses an inverted !!memcmp result in the GEN_IPADD branch when comparing an IP-literal host with a certificate IP SubjectAltName. OpenSSL builds reject matching IP addresses and accept mismatched IP addresses, allowing a network attacker with a CA-trusted certificate containing any IP SubjectAltName to intercept libgit2 connections to IP-literal HTTPS URLs. DNS SubjectAltName validation and non-OpenSSL TLS backends are not affected. This issue is fixed in versions 1.8.6 and 1.9.5.","publishedAt":"2026-08-20T19:16:54","lastModifiedAt":"2026-08-20T19:16:54","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53583","cvssScore":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","epssProbability":0.00192,"riskScore":0.66,"affectedProduct":"libgit2","affectedVersions":"<1.8.6, <1.9.5","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-53583","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-53583","en":"https://www.redsauce.net/en/cves/CVE-2026-53583","fr":"https://www.redsauce.net/fr/cves/CVE-2026-53583","pt":"https://www.redsauce.net/pt/cves/CVE-2026-53583","de":"https://www.redsauce.net/de/cves/CVE-2026-53583","sk":"https://www.redsauce.net/sk/cves/CVE-2026-53583","el":"https://www.redsauce.net/el/cves/CVE-2026-53583"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-53583"}}