# vLLM: Security Check Bypass via assert Statement in Activation Function Loading Allows Arbitrary Code Execution Advisory record · `GHSA-q8gq-377p-jq3r` - **Identifiers:** `GHSA-q8gq-377p-jq3r` · `CVE-2026-41523` · `PYSEC-2026-2300` - **State:** Confirmed - **Severity:** CVSS 7.5 High - **Critical:** No - **Weakness (CWE):** [CWE-94](https://cwe.mitre.org/data/definitions/94.html) · [CWE-617](https://cwe.mitre.org/data/definitions/617.html) - **Tags:** [Code injection](https://agentprime.io/advisories/tag/code-injection.md) · [Denial of service](https://agentprime.io/advisories/tag/dos.md) - **Published:** 16 Jun 2026 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 16 Jun 2026, 17:34 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `vllm` (PyPI): affected `<0.22.0`; fixed in `0.22.0` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > vLLM versions before 0.22.0 are affected. When vLLM runs in Python optimized mode (python -O or PYTHONOPTIMIZE=1), an assert-based check that restricts which activation functions can be loaded from a HuggingFace model's config.json is removed, so a malicious model publisher can cause arbitrary code execution on a victim's server when the victim loads a crafted cross-encoder model. Upgrade to vLLM 0.22.0 or later. The source gives no workaround beyond avoiding optimized mode and loading untrusted models. Written 4 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0091, the 60th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:29 UTC: First seen by agentprime - 31 Oct 2026, 14:29 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-q8gq-377p-jq3r) ## Sources - [GitHub Advisory Database: GHSA-q8gq-377p-jq3r](https://github.com/advisories/GHSA-q8gq-377p-jq3r) - [OSV: GHSA-q8gq-377p-jq3r](https://osv.dev/vulnerability/GHSA-q8gq-377p-jq3r) - - - - - - - - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .