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

> A malicious remote can cause a client panic and abort clone or fetch operations by sending a crafted pack header, affecting Gitoxide users.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 12 Oct 2026
- **Updated:** 13 Oct 2026
- **Also known as:** AZL-108084, AZL-108087, DEBIAN-CVE-2026-109349, GHSA-633h-mqjc-8rwg, GHSA-wmw6-cp8f-c6q8, UBUNTU-CVE-2026-109349

## What is CVE-2026-109349?

CVE-2026-109349 is a high-severity denial of service vulnerability in GitoxideLabs gix-pack, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2026-109349?


## How do I fix CVE-2026-109349?

Upgrade to a fixed version.

## Is CVE-2026-109349 being exploited?

There is no known exploitation of CVE-2026-109349 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109349 and fix it if it is affected.

What it is: CVE-2026-109349 is a high-severity denial of service vulnerability in GitoxideLabs gix-pack, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-109349 in the wild and no public exploit code.

Affected product: GitoxideLabs gix-pack. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-109349/ (Markdown: https://insights.sbomify.com/CVE-2026-109349/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109349
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109349
- OSV: https://osv.dev/vulnerability/CVE-2026-109349

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109349/
Summaries are generated and may contain mistakes; the official description above is the record.