TI-2026-38646 Aliases CVE-2026-53586

libgit2: HTTP transport can leak credentials to an offsite redirect target

LOW 29CWE-200Published 2026-08-20 · Updated 2026-08-21

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Information disclosure, Spoofing
Confidentiality · integrity · availability: High · None · None
Fix status: Partial Red Hat: 1 fixed, 4 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-200 and CWE-601.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00276 20th percentileScored 2026-11-07

Fix Partial libgit2 (libgit2): 1.8.6, 1.9.5Red Hat: 1 advisoryRed Hat: 1 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
libgit2	libgit2	before 1.8.6; 1.9.0 to before 1.9.5	1.8.6, 1.9.5	Patch available	CNA

libgit2 Vendorlibgit2 Affected before 1.8.6; 1.9.0 to before 1.9.5 Fixed in 1.8.6, 1.9.5 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:libgit2:libgit2::::::::	—	—	libgit2

cpe:2.3:a:libgit2:libgit2:*:*:*:*:*:*:*:* Versions — — ·libgit2

Remediation

Fix · CNA libgit2 (libgit2) Fixed in 1.8.6, 1.9.5

Red Hat 1 advisory

RHSA-2026:59361 Released 2026-08-25 · Red Hat rating Important
Red Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images libgit2-1.9.7-1.hum1@aarch64, libgit2-1.9.7-1.hum1@src, libgit2-1.9.7-1.hum1@x86_64 +2

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3	Affected	No fix yet: Fix deferred
Red Hat Hardened Images	Fixed	RHSA-2026:59361

Timeline

2026-10-02 Threatist record created from CVE-2026-53586

References

Other 6

TI-2014-07619 Git before 1.8.5.6, 1.9.x before 1.9.5, 2.0.x before 2.0.5, 2.1.x before 2.1.4, and 2.2.x… CVSS 3.1CRITICAL 9.8
TI-2026-38647 libgit2 - Unauthenticated network-reachable heap out-of-bounds read in transports/smart_pkt.c:set_data CVSS 3.1HIGH 7.5
TI-2026-38643 libgit2: Inverted IP SubjectAltName Comparison in OpenSSL Backend CVSS 3.1MEDIUM 6.5
TI-2026-38645 libgit2: Unbounded Memory Allocation via Delta Object Result-Size Header CVSS 3.1MEDIUM 5.3
TI-2024-16198 libgit2 is vulnerable to arbitrary code execution due to heap corruption in `git_index_add` CVSS 3.1CRITICAL 9.8
TI-2020-09811 An issue was discovered in libgit2 before 0.28.4 and 0.9x before 0.99.0. CVSS 3.1CRITICAL 9.8

See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences