VDB
CVE-2026-96640
CVE-2026-96640
PUBLISHED
CVSS 8.2 HIGH
Reported by GitHub_M · Published October 21, 2026
Pillow is a Python imaging library. From 5.1.0 until 13.0.0, PdfParser.linearize_page_tree() in src/PIL/PdfParser.py treats a PDF /Pages graph as a tree without tracking duplicate indirect references. When Image.save(..., format="PDF", append=True) processes an attacker-controlled existing PDF whose /Kids arrays repeatedly reference the same child /Pages node, Pillow expands the shared subtree as distinct pages. A compact malformed PDF can therefore create exponentially many page references and consume disproportionate CPU before the append completes. This issue is fixed in version 13.0.0.
Risk Scores
CVSS 4.0
8.2
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | >= 5.1.0, < 13.0.0 |
| chainguard | superset-fips-6.1 | 0 |
| PyPI | Pillow | 5.1.0 |
| chainguard | nemo-gym | 0 |
| chainguard | nemo-rl-cuda-13.0 | 0 |
| python-pillow | Pillow | 5.1.0 |
| chainguard | py3-pytorch-cuda-13.0 | 0 |
Timeline
- Oct 21, 2026 CVE Published
- Oct 22, 2026 EPSS Score
- Oct 22, 2026 Coalition ESS Score
- Oct 25, 2026 EPSS Score
- Oct 29, 2026 EPSS Score
- Oct 30, 2026 EPSS Score
- Oct 30, 2026 Distribution Patch
- Oct 30, 2026 Security Advisory
- Oct 30, 2026 Security Advisory
- Nov 3, 2026 Distribution Patch
References
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-mrfp-p49p-3hf2 x_refsource_CONFIRM
- https://github.com/python-pillow/Pillow/pull/10093 x_refsource_MISC
- https://github.com/python-pillow/Pillow/commit/6f0e7ee1f9c2fe227906f8a4b926e6622b702bc7 x_refsource_MISC
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0 x_refsource_MISC
- https://nvd.nist.gov/vuln/detail/CVE-2026-96640 advisory
- https://github.com/advisories/GHSA-mrfp-p49p-3hf2 advisory