# Pillow: Heap buffer overflow in ImagingJpegDecode Advisory record · `GHSA-8g5g-8vmr-9782` - **Identifiers:** `GHSA-8g5g-8vmr-9782` · `BIT-pillow-2026-112403` · `CVE-2026-112403` · `PYSEC-2026-4332` - **State:** Confirmed - **Severity:** CVSS 9.2 Critical - **Critical:** Yes: CVSS 9+ - **Weakness (CWE):** [CWE-122](https://cwe.mitre.org/data/definitions/122.html) - **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md) - **Published:** 20 Oct 2026 - **Updated:** 28 Oct 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 20 Oct 2026, 20:40 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Critical Critical, because: - CVSS score 9.2: 9.0 or more. How we decide what’s critical: ## Affected packages - `pillow` (PyPI): affected `<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 before 13.0.0 are affected by a heap buffer overflow in the JPEG decoder (ImagingJpegDecode). A specially crafted lossless (SOF3) JPEG file, when processed through the thumbnail path that calls draft(), causes writes past a heap allocation, so an attacker who can supply an image file can likely cause memory corruption. Upgrade to Pillow 13.0.0 or later, which contains the fix; avoiding thumbnail() with reducing_gap=None or calling load() first is a workaround noted in the source. 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 - 9.2 Critical, CVSS 4.0: `CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0095, the 61st percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 17 Oct 2026, 10:34 UTC: [Published by the maintainers as a GitHub repository advisory](https://github.com/python-pillow/Pillow/security/advisories/GHSA-8g5g-8vmr-9782) - 31 Oct 2026, 14:07 UTC: First seen by agentprime - 31 Oct 2026, 14:07 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-8g5g-8vmr-9782) ## Sources - [GitHub Advisory Database: GHSA-8g5g-8vmr-9782](https://github.com/advisories/GHSA-8g5g-8vmr-9782) - [OSV: GHSA-8g5g-8vmr-9782](https://osv.dev/vulnerability/GHSA-8g5g-8vmr-9782) - - - - - 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: .