# CVE-2026-109351: Gitoxide gix-pack before 0.75.0 Denial of Service via Pack Header Object Count

> Remote attackers can cause denial of service in Gitoxide gix-pack by sending malicious pack headers that trigger excessive memory allocation.

- **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:** 26 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-109351, GHSA-hf39-hrp5-hx3v, GHSA-x862-c2wj-4mwr, UBUNTU-CVE-2026-109351

## What is CVE-2026-109351?

CVE-2026-109351 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 an uncontrolled memory allocation vulnerability that allows remote attackers to abort the process by supplying a huge pack-header object count. Malicious remotes can serve a 12-byte pack header claiming 0xFFFFFFFF objects, forcing Tree::with_capacity to reserve hundreds of gigabytes and crash clone or fetch operations.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-109351?


## How do I fix CVE-2026-109351?

Upgrade to a fixed version.

## Is CVE-2026-109351 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109351 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109351 and fix it if it is affected.

What it is: CVE-2026-109351 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109351 exists.

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-2026-109351/ (Markdown: https://insights.sbomify.com/CVE-2026-109351/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109351
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109351
- OSV: https://osv.dev/vulnerability/CVE-2026-109351

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109351/
Summaries are generated and may contain mistakes; the official description above is the record.