Integer overflow in Psd-Tools
CVE-2026-27809
psd-tools is a Python package for working with Adobe Photoshop PSD files. Prior to version 1.12.2, when a PSD file contains malformed RLE-compressed image data (e.g. a literal run that extends past the expected row size), decode_rle() raises ValueError which propagated all the way to the user, crashing psd.composite() and psd-tools export. decompress() already had a fallback that replaces failed channels with black pixels when result is None, but it never triggered because the ValueError from decode_rle() was not caught. The fix in version 1.12.2 wraps the decode_rle() call in a try/except so the existing fallback handles the error gracefully.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (50.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 50.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003
Affected products
- Psd-Tools — versions < 1.12.2
- Psd-Tools Project
Weakness classification (CWE)
References
- github.com/psd-tools/psd-tools/security/advisories/GHSA-24p2-j2jr-386w (Exploit, Vendor Advisory)
- github.com/psd-tools/psd-tools/commit/6c0a78f195b5942757886a1863793fd5946c1fb1 (Patch)
- github.com/psd-tools/psd-tools/releases/tag/v1.12.2 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-27809?
- CVE-2026-27809 is a critical-severity vulnerability in Psd-Tools, classified under Integer Overflow or Wraparound. CVSS score: 9.1/10. Published 2026-02-26.
- How severe is CVE-2026-27809?
- Critical severity. CVSS v3 base score is 9.1 out of 10.