CVE-2026-53583

medium Red Hat
CVSS v3 Base Score
6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS Score
0.2%
Exploitation probability in 30 days
Top 91% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Published: August 20, 2026 (17 days ago)
Last Modified: August 20, 2026
Vendor: Red Hat
Fix Available: ✓ Yes
Source: REDHAT

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.

CWE

CWE-295

Affected Products

Red Hat Enterprise Linux 10Red Hat Enterprise Linux 8Red Hat Enterprise Linux 9Red Hat Enterprise Linux AI (RHEL AI) 3Red Hat Hardened Images

Fix Status

✅ Fix Available

References

🔗 bugzilla.redhat.com 🔗 www.cve.org 🔗 nvd.nist.gov 🔗 github.com 🔗 github.com