CVE-2026-96640: Pillow is a Python imaging library

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HIGH 8.2REMOTE

CVE-2026-96640 is a high-severity flaw (CVSS 8.2) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 theref

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-400, CWE-407
Published	2026-10-21
Last modified	2026-10-22

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-10-21Published CVE record published
2026-10-22 16:46 UTCUpdated Record last modified

Exact fixes by distribution

Python (pip) · Pillow · FIXED · 13.0.0 · vulnerable: >= 5.1.0, < 13.0.0 · source

pip install --upgrade "Pillow>=13.0.0" pip show Pillow

Fedora 46 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source

sudo dnf upgrade --advisory=FEDORA-2026-95888f332b

Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source

sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273

Debian 12 · pillow · NO FIX YET

Debian 13 · pillow · NO FIX YET

RHEL 8 · python-pillow · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-aws-cuda-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-azure-cuda-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-azure-rocm-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-cuda-rhel9 · NO FIX YET

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-96640?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-96640 being exploited?

CVE-2026-96640 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-96640 affect?

CVE-2026-96640 affects affected software. Severity is high (CVSS 8.2). 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", appe

How urgent is CVE-2026-96640?

Priority 43/100. High severity; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

References

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