# CVE-2026-26210: KTransformers Unsafe Deserialization RCE via balance_serve

> Attackers can execute arbitrary code on KTransformers servers by sending crafted pickle payloads to the exposed ZMQ socket in balance_serve mode.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/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:** 23 Apr 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-w598-p4vc-7qcx

## What is CVE-2026-26210?

CVE-2026-26210 is a critical unsafe deserialization vulnerability in kvcache-ai ktransformers, published on 23 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

KTransformers through 0.5.3 contains an unsafe deserialization vulnerability in the balance_serve backend mode where the scheduler RPC server binds a ZMQ ROUTER socket to all interfaces with no authentication and deserializes incoming messages using pickle.loads() without validation. Attackers can send a crafted pickle payload to the exposed ZMQ socket to execute arbitrary code on the server with the privileges of the ktransformers process.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-26210?

It affects 1 product.


Products: Kvcache-Ai Ktransformers.

## How do I fix CVE-2026-26210?

No fix has been published for CVE-2026-26210 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-26210 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-26210 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26210 and fix it if it is affected.

What it is: CVE-2026-26210 is a critical unsafe deserialization vulnerability in kvcache-ai ktransformers, published on 23 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-26210 exists.

Affected product: kvcache-ai ktransformers. 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-2026-26210/ (Markdown: https://insights.sbomify.com/CVE-2026-26210/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26210
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26210
- OSV: https://osv.dev/vulnerability/CVE-2026-26210

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26210/
Summaries are generated and may contain mistakes; the official description above is the record.