CVE-2026-54059

HIGH7.5

Pillow: PcfFontFile._load_bitmaps()`: `Image.frombytes()` called without `_decompression_bomb_check()` — bomb protection bypass via PCF font loading

Published Jul 6, 2026

Modified 2 weeks ago

Details

Pillow is a Python imaging library. Prior to 12.3.0, PIL/PcfFontFile.py _load_bitmaps() read glyph dimensions from the PCF METRICS section and passed them directly to Image.frombytes() without calling Image._decompression_bomb_check(), allowing crafted PCF font data to cause excessive memory allocation. This issue is fixed in version 12.3.0.

References

WEB

https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst

WEB

https://github.com/python-pillow/Pillow/commit/0a263e6264aa5399988d9acd3bbfbca2ca3ec77d

DETECTION

https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-54059

CVSS Analysis

CVSS v3.1

7.5