What’s Vulnerable › Vulnerabilities

CVE-2026-59203: Pillow EpsImagePlugin negative %%BeginBinary byte count causes infinite loop denial of service

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-14 · updated 2026-10-24
• Weakness: CWE-835

Description

Pillow is a Python imaging library. From 12.0.0 through 12.2.0, Pillow's EPS parser in PIL/EpsImagePlugin.py accepts a negative byte count in the %%BeginBinary directive, allowing a crafted EPS file to cause Image.open() to seek backwards to the same directive and parse it repeatedly in an infinite loop. This issue is fixed in version 12.3.0.

Affected products

• python-pillow Pillow: from 12.0.0 before 12.3.0 — fixed in 12.3.0

How to fix

Upgrade to a fixed version: python-pillow Pillow 12.3.0. Check the vendor advisory for mitigations.

References

• https://github.com/python-pillow/Pillow/commit/03992618118b4a76b6163cd72ab5ecd684133b83
• https://github.com/python-pillow/Pillow/pull/9708
• https://github.com/python-pillow/Pillow/releases/tag/12.3.0
• https://github.com/python-pillow/Pillow/security/advisories/GHSA-pg7v-jwj7-p798
• https://github.com/python-pillow/Pillow/security/advisories/GHSA-pg7v-jwj7-p798

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