# CVE-2026-107183: llama.cpp before b11393 Use-After-Free via common_chat_peg_mapper chat_parser

> Unauthenticated attackers can trigger a use-after-free in llama.cpp's chat parser via crafted requests, leading to heap corruption, crashes, or potential code execution.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/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:** Not needed
- **Fix available:** No
- **Published:** 7 Oct 2026
- **Updated:** 7 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-107183, GHSA-3g9g-qh2j-c5q8, UBUNTU-CVE-2026-107183

## What is CVE-2026-107183?

CVE-2026-107183 is a critical use after free vulnerability in ggml-org llama.cpp, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

llama.cpp before b11393 contains a use-after-free and double free vulnerability in common_chat_peg_mapper::map that allows unauthenticated remote attackers to corrupt heap memory via a dangling current_tool pointer. Attackers can submit a chat_parser in a POST /completion request emitting a tool-id after a tool-close tag to crash llama-server and shape a heap write primitive.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-107183?


## How do I fix CVE-2026-107183?

No fix has been published for CVE-2026-107183 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-107183 being exploited?

There is no known exploitation of CVE-2026-107183 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107183 and fix it if it is affected.

What it is: CVE-2026-107183 is a critical use after free vulnerability in ggml-org llama.cpp, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-107183 in the wild and no public exploit code.

Affected product: ggml-org llama.cpp. 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-2026-107183/ (Markdown: https://insights.sbomify.com/CVE-2026-107183/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107183
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107183
- OSV: https://osv.dev/vulnerability/CVE-2026-107183

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107183/
Summaries are generated and may contain mistakes; the official description above is the record.