Vulnerability · Published Feb 25, 2026 · Assigned by GitHub_M
CVE-2026-27809psd-tools: Compression module has unguarded zlib decompression, missing dimension validation, and hardening gaps
Medium 6.8
In plain English
A medium-severity integer overflow in psd-tools from psd-tools. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | psd-tools | no fix listed | DEBIAN-CVE-2026-27809 |
| Debian:13 | psd-tools | 1.10.7+dfsg.1-1+deb13u1 | DEBIAN-CVE-2026-27809 |
| Debian:14 | psd-tools | 1.14.2+dfsg.1-1 | DEBIAN-CVE-2026-27809 |
| PyPI | psd-tools | 1.12.2 | GHSA-24p2-j2jr-386w |
| PyPI | psd-tools | 1.12.2 | PYSEC-2026-2262 |
| Ubuntu:24.04:LTS | psd-tools | no fix listed | UBUNTU-CVE-2026-27809 |
| Ubuntu:25.10 | psd-tools | no fix listed | UBUNTU-CVE-2026-27809 |
| Ubuntu:26.04:LTS | psd-tools | no fix listed | UBUNTU-CVE-2026-27809 |
| Ubuntu:26.10 | psd-tools | no fix listed | UBUNTU-CVE-2026-27809 |
Affected products (as reported)
Weakness: CWE-409, CWE-789, CWE-617, CWE-190, CWE-755, CWE-704 · 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