Summary
Workarounds
Image.open() has a formats parameter that can be used to prevent PSD images from being opened.
References
Pillow 12.1.1 will add release notes at https://pillow.readthedocs.io/en/stable/releasenotes/index.html
Impact
An out-of-bounds write may be triggered when loading a specially crafted PSD image. Pillow >= 10.3.0 users are affected.
A write operation targets a memory location beyond the intended buffer boundary. Typical impact: memory corruption, crash, or arbitrary code execution.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Pillow 12.1.1 will be released shortly with a fix for this.
Frequently Asked Questions
- What is CVE-2026-25990? CVE-2026-25990 is a high-severity out-of-bounds write vulnerability in pillow (pip), affecting versions >= 10.3.0, < 12.1.1. It is fixed in 12.1.1. A write operation targets a memory location beyond the intended buffer boundary.
- Which versions of pillow are affected by CVE-2026-25990? pillow (pip) versions >= 10.3.0, < 12.1.1 is affected.
- Is there a fix for CVE-2026-25990? Yes. CVE-2026-25990 is fixed in 12.1.1. Upgrade to this version or later.
- Is CVE-2026-25990 exploitable, and should I be worried? Whether CVE-2026-25990 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-25990 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-25990? Upgrade
pillowto 12.1.1 or later.