# Pillow: MSP RLE decoder expands a tiny file into unbounded memory

Advisory record · `GHSA-gg2r-wvfm-q9rx`

- **Identifiers:** `GHSA-gg2r-wvfm-q9rx` · `BIT-pillow-2026-112892` · `CVE-2026-112892`
- **State:** Confirmed
- **Severity:** CVSS 8.7 High
- **Critical:** No
- **Weakness (CWE):** [CWE-409](https://cwe.mitre.org/data/definitions/409.html)
- **Tags:** [CWE-409](https://agentprime.io/advisories/tag/cwe-409.md)
- **Published:** 21 Oct 2026
- **Updated:** 26 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 21 Oct 2026, 21:12 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `pillow` (PyPI): affected `>=4.1.0, <13.0.0`; fixed in `13.0.0`

## Machine-written summary

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

> Pillow versions from 4.1.0 before 13.0.0 are affected by a flaw in the MSP RLE decoder, which expands run-length data into an in-memory buffer without a limit tied to the declared image size. A small crafted MSP file can force very large memory allocation when an application loads its pixels, causing a denial of service; the source notes that the pixel-count limit does not bound this expansion. Upgrade to Pillow 13.0.0 or later, which contains the fix.

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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0050, the 43rd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:07 UTC: First seen by agentprime
- 31 Oct 2026, 14:07 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-gg2r-wvfm-q9rx)

## Sources

- [GitHub Advisory Database: GHSA-gg2r-wvfm-q9rx](https://github.com/advisories/GHSA-gg2r-wvfm-q9rx)
- [OSV: GHSA-gg2r-wvfm-q9rx](https://osv.dev/vulnerability/GHSA-gg2r-wvfm-q9rx)
- <https://github.com/python-pillow/Pillow/security/advisories/GHSA-gg2r-wvfm-q9rx>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-112892>
- <https://github.com/python-pillow/Pillow/commit/5dcb630b9798efd91929cb873d677aeee6ed0bb3>
- <https://github.com/python-pillow/Pillow>
- <https://github.com/python-pillow/Pillow/releases/tag/13.0.0>

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-gg2r-wvfm-q9rx>, 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-gg2r-wvfm-q9rx/>. Everything for agents: <https://agentprime.io/llms.txt>.