What’s Vulnerable › Vulnerabilities

CVE-2026-59204: Pillow JPEG2000 tiled decode retains a growing scratch buffer and can be used for 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-789

Description

Pillow is a Python imaging library. From 8.2.0 through 12.2.0, src/libImaging/Jpeg2KDecode.c accumulates total_component_width across every tile in a JPEG2000 image instead of recomputing it per tile, allowing a crafted tiled JPEG2000 file to force substantially higher transient memory usage and trigger out-of-memory failures during decoding. This issue is fixed in version 12.3.0.

Affected products

• python-pillow Pillow: from 8.2.0 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/13ada41172142f2fd9f0906f615a00ea623a11ca
• https://github.com/python-pillow/Pillow/pull/9704
• https://github.com/python-pillow/Pillow/releases/tag/12.3.0
• https://github.com/python-pillow/Pillow/security/advisories/GHSA-vjc4-5qp5-m44j
• https://github.com/python-pillow/Pillow/security/advisories/GHSA-vjc4-5qp5-m44j

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