# zbateson/mail-mime-parser has uncontrolled resource consumption (CPU/memory DoS) parsing untrusted MIME

Advisory record · `GHSA-f6v3-2qmr-vfjx`

- **Identifiers:** `GHSA-f6v3-2qmr-vfjx` · `CVE-2026-61816` · `PKSA-r8x8-972m-nrc1`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **Weakness (CWE):** [CWE-400](https://cwe.mitre.org/data/definitions/400.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 24 Sept 2026
- **Updated:** 24 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 24 Sept 2026, 19:45 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `zbateson/mail-mime-parser` (Packagist): affected `>=2.0.0, <3.0.6 || >=4.0.0, <4.0.2`; fixed in `3.0.6`, `4.0.2`

## Machine-written summary

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

> The zbateson/mail-mime-parser Packagist package, versions >=2.0.0 <3.0.6 and >=4.0.0 <4.0.2, is affected. An attacker who can submit a crafted email under 2 MB to an application that parses it can cause high CPU use and memory exhaustion, leading to denial of service. Upgrade to 3.0.6 or 4.0.2, the fixed versions.

Written 31 Oct 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:L/PR:N/UI:N/S:U/C:N/I:N/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0039, the 33rd percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 13:54 UTC: First seen by agentprime
- 31 Oct 2026, 13:54 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-f6v3-2qmr-vfjx)

## Sources

- [GitHub Advisory Database: GHSA-f6v3-2qmr-vfjx](https://github.com/advisories/GHSA-f6v3-2qmr-vfjx)
- [OSV: GHSA-f6v3-2qmr-vfjx](https://osv.dev/vulnerability/GHSA-f6v3-2qmr-vfjx)
- <https://github.com/zbateson/mail-mime-parser/security/advisories/GHSA-f6v3-2qmr-vfjx>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-61816>
- <https://github.com/zbateson/mail-mime-parser/commit/1691e695821f70461f9554e9bb71be2859404a24>
- <https://github.com/zbateson/mail-mime-parser/commit/fa44823ba9dd651e0eecec7aa45ac8c8e6afcb78>
- <https://github.com/zbateson/mail-mime-parser>
- <https://github.com/zbateson/mail-mime-parser/releases/tag/3.0.7>
- <https://github.com/zbateson/mail-mime-parser/releases/tag/4.0.2>

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-f6v3-2qmr-vfjx>, 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-f6v3-2qmr-vfjx/>. Everything for agents: <https://agentprime.io/llms.txt>.