CVE-2026-54059

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

Published: Jul 6, 2026Updated: Jul 7, 2026 Sources: CVE List NVDCWE-789

7.5HIGH

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:HAvailability

High

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Weaknesses

CWE-789

Affected Products

oss-project·US

oss-projectaka pillow

PillowLibrary

OSS Libraries / pypi

Exploitability

Official Patch Available

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References

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

github.com

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

github.com

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

github.com

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