CVE-2026-27809 MEDIUM

CVE-2026-27809: psd-tools: Compression module has unguarded zlib decompression, missing dimension validation, and hardening gaps

Vendor Psd-Tools
Product psd-tools
Weakness CWE-409
Published February 25, 2026
Last update February 26, 2026

CVSS base score

6.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

February 25, 2026 CVE published
February 26, 2026 Record updated