CVE-2026-54059

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

Description

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.

Scores

Weaknesses (CWE)

• CWE-789

Advisories

• GHSA-8v84-f9pq-wr9x — Pillow `PcfFontFile._load_bitmaps()`: `Image.frombytes()` called without `_decompression_bomb_check()` — bomb protection bypass via PCF font loading
• PYSEC-2026-2253 — 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 direc

European references

• ENISA EUVD · EUVD-2026-41899
• GCVE · GCVE-0-2026-54059

CERT-FR advisories

• CERTFR-2026-AVI-1366 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
• CERTFR-2026-AVI-1094 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

• cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* < 12.3.0

Affected products

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x
• https://github.com/python-pillow/Pillow/commit/0a263e6264aa5399988d9acd3bbfbca2ca3ec77d
• https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst

Sources