CVE-2026-96637: Pillow is a Python imaging library

Routine

HIGH 7.1

CVE-2026-96637 is a high-severity flaw (CVSS 7.1) 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. Prior to 13.0.0, SpiderImageFile.seek() in src/PIL/SpiderImagePlugin.py reparses a later SPIDER stack frame and replaces self._size without rerunning Image._decompression_bomb_check(). A tiny file can use a safe first frame to pass Image.open() and then declare very large dimensions in a later mode F frame. Loading that frame allocates approximately four bytes per attacker-declared pixel and can consume multipl

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Passive
EPSS exploit chance	0.3% (top 75%)
CISA exploited list	No
Weakness	CWE-400, CWE-409
Published	2026-10-21
Last modified	2026-10-23

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-10-21 21:20 UTCPublished CVE record published
2026-10-23 22:17 UTCUpdated Record last modified

Exact fixes by distribution

Python (pip) · pillow · FIXED · 13.0.0 · vulnerable: < 13.0.0 · source

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

Fedora 46 · diffoscope · FIXED · 335-1.fc46 · FEDORA-2026-e4c4cc0856 · source

sudo dnf upgrade --advisory=FEDORA-2026-e4c4cc0856

Debian 12 · pillow · NO FIX YET

Debian 13 · pillow · NO FIX YET

RHEL 8 · python-pillow · DEFERRED

RHEL AI (RHEL AI) 3 · rhelai3/bootc-aws-cuda-rhel9 · DEFERRED

RHEL AI (RHEL AI) 3 · rhelai3/bootc-azure-cuda-rhel9 · DEFERRED

RHEL AI (RHEL AI) 3 · rhelai3/bootc-azure-rocm-rhel9 · DEFERRED

RHEL AI (RHEL AI) 3 · rhelai3/bootc-cuda-rhel9 · DEFERRED

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-2026-96637?

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

Is CVE-2026-96637 being exploited?

CVE-2026-96637 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-2026-96637 affect?

CVE-2026-96637 affects affected software. Severity is high (CVSS 7.1). Pillow is a Python imaging library. Prior to 13.0.0, SpiderImageFile.seek() in src/PIL/SpiderImagePlugin.py reparses a later SPIDER stack frame and replaces self._size without rerunning Image._decompression_bomb_check(). A tiny file can use

How urgent is CVE-2026-96637?

Priority 31/100. High severity

Software pages

Python vulnerabilities

References

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