# CVE-2026-43632: llama.cpp b7492–b9060 Use-After-Free in Tokenization Endpoints

> Attackers can trigger a use-after-free in llama-server tokenization endpoints via a race condition, potentially causing crashes or code execution when idle sleep is enabled.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:H/AT:P/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:** 6 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-43632, GHSA-3f2h-96vw-c84x, UBUNTU-CVE-2026-43632

## What is CVE-2026-43632?

CVE-2026-43632 is a critical use after free vulnerability in ggml-org llama.cpp, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

llama.cpp builds b7492 through the latest b9060 contains a use-after-free vulnerability in llama-server affecting six tokenization endpoints (/tokenize, /detokenize, /infill, /apply-template, /rerank, and /anthropic/count_tokens) that bypass the task queue and access ctx_server.vocab directly on HTTP worker threads. Attackers can exploit a time-of-check-time-of-use race condition where the main thread destroys and frees vocab after the synchronization lock is released but before the handler finishes using it, causing a crash or potential code execution when --sleep-idle-seconds is configured.

Weakness: CWE-416 (Use After Free), CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2026-43632?

It affects 1 product.


Products: Ggml Llama.cpp.

## How do I fix CVE-2026-43632?

No fix has been published for CVE-2026-43632 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-43632 being exploited?

There is no known exploitation of CVE-2026-43632 in the wild and no public exploit code.

## Other vulnerabilities in ggml-org llama.cpp

- [CVE-2024-42479](https://insights.sbomify.com/CVE-2024-42479/): llama.cpp allows write-what-where in rpc_server::set_tensor (critical 10.0)
- [CVE-2026-34159](https://insights.sbomify.com/CVE-2026-34159/): llama.cpp: Unauthenticated RCE via GRAPH_COMPUTE buffer=0 bypass in llama.cpp RPC backend (critical 9.8)
- [CVE-2026-43629](https://insights.sbomify.com/CVE-2026-43629/): llama.cpp b4882–b9058 Buffer Overflow in KV Cache State Restore (critical 9.2)
- [CVE-2026-43631](https://insights.sbomify.com/CVE-2026-43631/): llama.cpp b7492–b9060 Use-After-Free RCE via llama-server (critical 9.2)
- [CVE-2026-21869](https://insights.sbomify.com/CVE-2026-21869/): llama.cpp has Out-of-bounds Write in llama-server (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43632 and fix it if it is affected.

What it is: CVE-2026-43632 is a critical use after free vulnerability in ggml-org llama.cpp, published on 6 Aug 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-2026-43632 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-2026-43632/ (Markdown: https://insights.sbomify.com/CVE-2026-43632/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43632
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43632
- OSV: https://osv.dev/vulnerability/CVE-2026-43632

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43632/
Summaries are generated and may contain mistakes; the official description above is the record.