CVE-2026-96640
highPillow is a Python imaging library.
Vendor / product: Python — pillow
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/python-pillow/Pillow/commit/6f0e7ee1f9c2fe227906f8a4b926e6622b702bc7 security-advisories@github.com
- https://github.com/python-pillow/Pillow/pull/10093 security-advisories@github.com
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0 security-advisories@github.com
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-mrfp-p49p-3hf2 security-advisories@github.com
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-mrfp-p49p-3hf2 134c704f-9b21-4f2e-91b3-4a467353bcc0