CVE-2026-25990: Pillow Pillow Affected By Out-of-bounds Write Vulnerability

HIGH
Advisory Identifier: GHSA-cfh3-3jmp-rvhc
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CWE-787
Published
Advisory Summary

CVE-2026-25990 is a HIGH pillow affected by out-of-bounds write vulnerability (CWE-787: Out-of-bounds Write) affecting Pillow libraries in the PyPI ecosystem. The issue involves pillow affected by out-of-bounds write when loading psd images. Remediation is available by upgrading affected packages to version 12.1.1.

CVE-2026-25990 at a Glance

CVE Identifier CVE-2026-25990
GHSA Identifier GHSA-cfh3-3jmp-rvhc
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Pillow
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-25990

To remediate this vulnerability, upgrade all affected Pillow dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pillow fixed: 12.1.1 
pip install pillow>=12.1.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show pillow

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-25990, inspect your installed packages using pip:

pip show pillow

Analyze the terminal output to locate any version of Pillow in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 12.1.1), your application is affected.

Note: The pip show pillow command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-787: Out-of-bounds Write, where the product writes data past the end, or before the beginning, of the intended buffer. In Pillow, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact An out-of-bounds write may be triggered when loading a specially crafted PSD image. Pillow >= 10.3.0 users are affected. ### Patches Pillow 12.1.1 will be released shortly with a fix for this. ### 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

CVE-2026-25990 Affected Pillow Versions

1 component(s)
Fixed Versions:
12.1.1
Product / Package Ecosystem Affected Versions Fixed Version
pillow
pypi/pillow
PyPI
≥ 10.3.0
< 12.1.1
12.1.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/python-pillow/Pillow/security/advisories/GHSA-cfh3-3jmp-rvhc
NVD — CVE-2026-25990 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25990
Pillow Source Repository REPOSITORY
https://github.com/python-pillow/Pillow/pull/9427
Security Fix Commit FIX COMMIT
https://github.com/python-pillow/Pillow/commit/54ba4db542ad3c7b918812a4e2d69c27735a3199
Security Fix Commit FIX COMMIT
https://github.com/python-pillow/Pillow/commit/9000313cc5d4a31bdcdd6d7f0781101abab553aa
Pillow Source Repository REPOSITORY
https://github.com/python-pillow/Pillow
Pillow Release RELEASE
https://pillow.readthedocs.io/en/stable/releasenotes/12.1.1.html

Frequently Asked Questions

What is CVE-2026-25990?
CVE-2026-25990 is a security vulnerability in Pillow involving Pillow affected by out-of-bounds write when loading PSD images under CWE-787: Out-of-bounds Write.
Which Pillow versions are affected?
Affected versions include releases prior to 12.1.1 across affected packages: pillow.
What version fixes CVE-2026-25990?
Upgrading to 12.1.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pillow affected?
Yes, pillow is affected in releases prior to 12.1.1. Upgrade your dependency to 12.1.1 or later.
What CWE is associated with CVE-2026-25990?
CVE-2026-25990 is classified under CWE-787: Out-of-bounds Write (The product writes data past the end, or before the beginning, of the intended buffer.).
How can I check PyPI dependencies for CVE-2026-25990?
Run the dependency tree command: 'pip show pillow'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cfh3-3jmp-rvhc",
  "modified" : "2026-04-30T20:14:47Z",
  "published" : "2026-02-11T14:22:50Z",
  "aliases" : [ "CVE-2026-25990" ],
  "summary" : "Pillow affected by out-of-bounds write when loading PSD images",
  "details" : "### Impact\nAn out-of-bounds write may be triggered when loading a specially crafted PSD image. Pillow >= 10.3.0 users are affected.\n\n### Patches\nPillow 12.1.1 will be released shortly with a fix for this.\n\n### Workarounds\n`Image.open()` has a `formats` parameter that can be used to prevent PSD images from being opened.\n\n### References\nPillow 12.1.1 will add release notes at https://pillow.readthedocs.io/en/stable/releasenotes/index.html",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pillow"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.3.0"
      }, {
        "fixed" : "12.1.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/python-pillow/Pillow/security/advisories/GHSA-cfh3-3jmp-rvhc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-25990"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-pillow/Pillow/pull/9427"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-pillow/Pillow/commit/54ba4db542ad3c7b918812a4e2d69c27735a3199"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-pillow/Pillow/commit/9000313cc5d4a31bdcdd6d7f0781101abab553aa"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/python-pillow/Pillow"
  }, {
    "type" : "WEB",
    "url" : "https://pillow.readthedocs.io/en/stable/releasenotes/12.1.1.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-11T14:22:50Z",
    "nvd_published_at" : "2026-02-11T21:16:20Z"
  }
}