# CVE-2026-10813: LMCache KV Cache utils.py hex_hash_to_int16 weak hash

> A weak hash function in LMCache allows local attackers to potentially bypass security checks, requiring high complexity to exploit.

- **Severity:** Low 2.0 (`CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Jun 2026
- **Updated:** 17 Oct 2026
- **Also known as:** GHSA-3hh9-752g-5g22, MINI-cxxw-w693-346v, MINI-m9gr-xh23-q53v, PYSEC-2026-3480

## What is CVE-2026-10813?

CVE-2026-10813 is a low-severity vulnerability in LMCache, published on 4 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw has been found in LMCache up to 0.5.4. This affects the function hex_hash_to_int16 of the file lmcache/integration/vllm/utils.py of the component KV Cache Handler. Executing a manipulation can lead to use of weak hash. The attack needs to be launched locally. The attack requires a high level of complexity. It is indicated that the exploitability is difficult. The exploit has been published and may be used. Upgrading to version 0.5.5 is able to mitigate this issue. This patch is called ce08eea76ce5898200efee55f4932fd07a7cabeb. It is suggested to upgrade the affected component. A contributor of the project confirms: "hex_hash_to_int16() was introduced in 0.3.1 (PR #882, commit f5174701). It is not present in 0.3.0, and it is still present in 0.4.7 through 0.5.4."

Weakness: CWE-328 (Use of Weak Hash), CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2026-10813?

3 open source packages ship an affected version, including lmcache.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `lmcache` | PyPI | All versions to 0.4.6 | None |
| `lmcache` | PyPI | All versions to 0.4.6 | None |
| `lmcache` | PyPI | All versions to 0.4.6 | None |

## How do I fix CVE-2026-10813?

Upgrade to a fixed version.

## Is CVE-2026-10813 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-10813 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10813 and fix it if it is affected.

What it is: CVE-2026-10813 is a low-severity vulnerability in LMCache, published on 4 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-10813 exists.

Affected packages and fixed versions:
- lmcache (PyPI): affected all versions up to 0.4.6; no fix listed
- lmcache (PyPI): affected all versions up to 0.4.6; no fix listed
- lmcache (PyPI): affected all versions up to 0.4.6; no fix listed

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-2026-10813/ (Markdown: https://insights.sbomify.com/CVE-2026-10813/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10813
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10813
- OSV: https://osv.dev/vulnerability/CVE-2026-10813

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-10813/
Summaries are generated and may contain mistakes; the official description above is the record.