What’s Vulnerable › Vulnerabilities

CVE-2021-25288: Pillow Out-of-bounds Read vulnerability

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-02 · updated 2026-06-17
• Weakness: CWE-125

Description

An issue was discovered in Pillow before 8.2.0. There is an out-of-bounds read in J2kDecode, in j2ku_gray_i.

Affected products

• Fedoraproject Fedora: 33
• python-pillow Pillow: before 8.2.0 — fixed in 8.2.0
• Pypi Pillow: before 8.2.0; 1.0, 1.1, 1.2, 1.3, 1.4, 1.5 (+73) — fixed in 8.2.0

How to fix

Upgrade to a fixed version: python-pillow Pillow 8.2.0; Pypi Pillow 8.2.0. Check the vendor advisory for mitigations.

References

• https://github.com/python-pillow/Pillow/pull/5377#issuecomment-833821470
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MQHA5HAIBOYI3R6HDWCLAGFTIQP767FL/
• https://pillow.readthedocs.io/en/stable/releasenotes/8.2.0.html#cve-2021-25287-cve-2021-25288-fix-oob-read-in-jpeg2kdecode
• https://security.gentoo.org/glsa/202107-33
• https://github.com/python-pillow/Pillow/pull/5377#issuecomment-833821470
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MQHA5HAIBOYI3R6HDWCLAGFTIQP767FL/
• https://pillow.readthedocs.io/en/stable/releasenotes/8.2.0.html#cve-2021-25287-cve-2021-25288-fix-oob-read-in-jpeg2kdecode
• https://security.gentoo.org/glsa/202107-33

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