# Pillow multi-frame loaders can reuse stale native image storage after mode transitions Advisory record · `GHSA-v9pv-5gc8-w2m6` - **Identifiers:** `GHSA-v9pv-5gc8-w2m6` · `BIT-pillow-2026-96639` · `CVE-2026-96639` · `PYSEC-2026-4339` - **State:** Confirmed - **Severity:** CVSS 9.8 Critical - **Critical:** Yes: CVSS 9+ - **Weakness (CWE):** [CWE-125](https://cwe.mitre.org/data/definitions/125.html) · [CWE-787](https://cwe.mitre.org/data/definitions/787.html) - **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md) - **Published:** 22 Oct 2026 - **Updated:** 29 Oct 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 22 Oct 2026, 16:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Critical Critical, because: - CVSS score 9.8: 9.0 or more. How we decide what’s critical: ## Affected packages - `pillow` (PyPI): affected `>=11.0.0, <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 11.0.0 up to but not including 13.0.0 are affected. A crafted multi-frame image (such as PSD, MPO, DCX, or MIC) can cause a later frame to decode into native image storage allocated for an earlier frame with a different mode, leading to out-of-bounds writes and process crashes. The report also describes command execution in a test environment via the MPO/JPEG path, with an attacker needing only to submit a crafted image to a service that processes it with Pillow. Upgrade to Pillow 13.0.0 or later, which is the listed fixed version. 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 - 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0066, the 51st 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-v9pv-5gc8-w2m6) ## Sources - [GitHub Advisory Database: GHSA-v9pv-5gc8-w2m6](https://github.com/advisories/GHSA-v9pv-5gc8-w2m6) - [OSV: GHSA-v9pv-5gc8-w2m6](https://osv.dev/vulnerability/GHSA-v9pv-5gc8-w2m6) - - - - - - 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: .