# CVE-2026-42309: pillow — Fixed in 12.2.0 🐍 PyPI Not in CISA KEV # CVE-2026-42309 — pillow [Fix: designcomputer/mysql\_mcp\_server@a96549f](https://github.com/designcomputer/mysql_mcp_server/commit/a96549f4a4d65443fd6e9c7f2324fba9a5c80a82) CVE-2026-42309 is a CWE-122 vulnerability in pillow. A fix is available for pillow — see the affected versions and patch details below. Pillow: Heap buffer overflow with nested list coordinates Also known asBIT-pillow-2026-42309[GHSA-5xmw-vc9v-4wf2](/vulnerability/GHSA-5xmw-vc9v-4wf2)PYSEC-2026-2251 Published May 9, 2026 Updated Oct 28, 2026 Affected 1 pkg Patched 1 / 1 Exploits None indexed Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS) ## Exploitation Status ### No confirmed exploitation observed yet - CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment. Exploitation and automatability from CISA’s SSVC triage for CVE-2026-42309. ## EPSS Exploitation Probability [via FIRST.org ↗](https://www.first.org/epss/) 0.1%probability of exploitation in next 30 days Lower Risk0.00% Lower risk than most CVEs3th percentile — riskier than 3% of all scored CVEsHighest risk 0.00%0.23%0.45%0.68%0.0%0.1%Jun 26Sep 26Nov 26 Probability of exploitation in the next 30 days, from [FIRST.org EPSS](https://www.first.org/epss/). ## Real-World Exposure 1 pkg affected 🐍`pillow` Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems. ## Description Pillow is a Python imaging library. From version 11.2.1 to before version 12.2.0, passing nested lists as coordinates to APIs that accept coordinates such as ImagePath.Path, ImageDraw.ImageDraw.polygon and ImageDraw.ImageDraw.line could cause a heap buffer overflow, as nested lists were recursively unpacked beyond the allocated buffer. Coordinate lists are now validated to contain exactly two numeric coordinates. This issue has been patched in version 12.2.0. ## Affected Packages 1 total 1 fixed Ecosystem Package Vulnerable range Fix 🐍PyPI `pillow` ≥ 11.2.1&&< 12.2.0 12.2.0`pip install --upgrade 'pillow==12.2.0'` ## Affected Products 1 product · 1 configurations Application `pillow`python ≥ 11.2.1 && < 12.2.0 range ## Detection & mitigation playbook Open-source dependency 1. ### Detect Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pillow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version. 2. ### Fix Update pillow to 12.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42309 is resolved across your whole dependency graph. 3. ### Workarounds Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process. ## Fixing This On Your OS If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project. Red HatModerate This Moderate impact vulnerability in the Pillow Python imaging library could lead to a denial of service. Applications processing untrusted image data that utilize specific Pillow APIs, such as \`ImagePath.Path\`, \`ImageDraw.ImageDraw.polygon\`, or \`ImageDraw.ImageDraw.line\`, with specially crafted nested list… Product Fixed in Advisory Red Hat AI Inference Server 3.3 `rhaiis/model-opt-cuda-rhel9:1778244559` [RHSA-2026:16008](https://access.redhat.com/errata/RHSA-2026:16008) Red Hat AI Inference Server 3.3 `rhaiis/vllm-rocm-rhel9:1778244531` [RHSA-2026:16009](https://access.redhat.com/errata/RHSA-2026:16009) Red Hat AI Inference Server 3.3 `rhaiis/vllm-cuda-rhel9:1778274666` [RHSA-2026:16030](https://access.redhat.com/errata/RHSA-2026:16030) Red Hat AI Inference Server 3.4 `rhaii/vllm-spyre-rhel9:1787151840` [RHSA-2026:57387](https://access.redhat.com/errata/RHSA-2026:57387) UbuntuMEDIUM [USN-8399-1Ubuntu](https://ubuntu.com/security/notices/USN-8399-1) ## Frequently Asked Questions Pillow is a Python imaging library. From version 11.2.1 to before version 12.2.0, passing nested lists as coordinates to APIs that accept coordinates such as ImagePath.Path, ImageDraw.ImageDraw.polygon and ImageDraw.ImageDraw.line could cause a heap buffer overflow, as nested lists were recursively unpacked beyond the allocated buffer. Coordinate lists are now validated to contain exactly two numeric coordinates. This issue has been patched in version 12.2.0. O3 Security · Impact-Aware SCA ### Is CVE-2026-42309 in your dependencies? Find it across PyPI, including transitive dependencies. [Scan my dependencies](/book-demo) [How O3 SCA works](/impact-aware-sca)