CVE-2026-109349: gix-pack before 0.75.0 Reachable Assertion DoS via Pack Version 3 Header

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-12 · updated 2026-10-16
Weakness: CWE-617

Description

gitoxide gix-pack before 0.75.0 contains a reachable assertion in BytesToEntriesIter::new_from_header: the pack header decoder accepts version 3, but a release-enabled assert_eq! requires version 2. A malicious remote can send a 12-byte pack header declaring version 3 to panic the client and abort the clone or fetch.

Affected products

GitoxideLabs gix-pack: before 0.75.0 — fixed in 0.75.0

How to fix

Upgrade to a fixed version: GitoxideLabs gix-pack 0.75.0. Check the vendor advisory for mitigations.

References

https://github.com/GitoxideLabs/gitoxide/security/advisories/GHSA-633h-mqjc-8rwg
https://www.vulncheck.com/advisories/gix-pack-before-0.75.0-reachable-assertion-dos-via-pack-version-3-header

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