# Guest-controlled resource exhaustion in WASI implementations

Advisory record · `GHSA-852m-cvvp-9p4w`

- **Identifiers:** `GHSA-852m-cvvp-9p4w` · `CVE-2026-27204` · `RUSTSEC-2026-0020`
- **State:** Confirmed
- **Severity:** CVSS 6.9 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-400](https://cwe.mitre.org/data/definitions/400.html) · [CWE-770](https://cwe.mitre.org/data/definitions/770.html) · [CWE-774](https://cwe.mitre.org/data/definitions/774.html) · [CWE-789](https://cwe.mitre.org/data/definitions/789.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md) · [CWE-774](https://agentprime.io/advisories/tag/cwe-774.md)
- **Published:** 24 Feb 2026
- **Updated:** 12 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 24 Feb 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `wasmtime` (crates.io): affected `>=0.0.0-0, <24.0.6 || >=25.0.0, <36.0.6 || >=37.0.0, <40.0.4 || >=41.0.0, <41.0.4`; fixed in `24.0.6`, `36.0.6`, `40.0.4`, `41.0.4`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The wasmtime crate (Rust) versions before 24.0.6, 25.0.0 through 36.0.5, 37.0.0 through 40.0.3, and 41.0.0 through 41.0.3 are affected. A guest module running inside the runtime can exhaust host resources through WASI implementations, which the source describes as guest-controlled resource exhaustion. The source gives few details on the exact trigger or impact. Upgrade to 24.0.6, 36.0.6, 40.0.4, or 41.0.4, depending on the release line in use.

Written 3 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

- 6.9 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0040, the 34th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:24 UTC: First seen by agentprime
- 31 Oct 2026, 14:24 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/RUSTSEC-2026-0020)

## Sources

- [GitHub Advisory Database: GHSA-852m-cvvp-9p4w](https://github.com/advisories/GHSA-852m-cvvp-9p4w)
- [OSV: GHSA-852m-cvvp-9p4w](https://osv.dev/vulnerability/GHSA-852m-cvvp-9p4w)
- <https://crates.io/crates/wasmtime>
- <https://rustsec.org/advisories/RUSTSEC-2026-0020.html>

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 (<https://api.agentprime.io/mcp>), 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: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-852m-cvvp-9p4w>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-852m-cvvp-9p4w/>. Everything for agents: <https://agentprime.io/llms.txt>.