What’s Vulnerable › Vulnerabilities

CVE-2021-25290: Out-of-bounds Write in Pillow

• Severity: high (CVSS 7.5 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: 2021-03-19 · updated 2026-06-17
• Weakness: CWE-787

Description

An issue was discovered in Pillow before 8.1.1. In TiffDecode.c, there is a negative-offset memcpy with an invalid size.

Affected products

• Debian Linux: 9.0
• python-pillow Pillow: before 8.1.1 — fixed in 8.1.1
• Pypi Pillow: before 8.1.1; 1.0, 1.1, 1.2, 1.3, 1.4, 1.5 (+71) — fixed in 8.1.1

How to fix

Upgrade to a fixed version: python-pillow Pillow 8.1.1; Pypi Pillow 8.1.1. Check the vendor advisory for mitigations.

References

• https://lists.debian.org/debian-lts-announce/2021/07/msg00018.html
• https://pillow.readthedocs.io/en/stable/releasenotes/8.1.1.html
• https://security.gentoo.org/glsa/202107-33
• https://lists.debian.org/debian-lts-announce/2021/07/msg00018.html
• https://pillow.readthedocs.io/en/stable/releasenotes/8.1.1.html
• https://security.gentoo.org/glsa/202107-33

Get alerted when CVE-2021-25290 or the next vulnerability affects your stack