What is CVE-2026-54059?

CVE-2026-54059 is a high-severity vulnerability in Python Pillow, classified under CWE-789. CVSS score: 7.5/10. Published 2026-07-06.

How severe is CVE-2026-54059?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Python Pillow

CVE-2026-54059

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.

Published 2026-07-06 · last modified 2026-07-07.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (33.1th percentile), scored 2026-10-08.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Python Pillow
Python-Pillow Pillow — versions < 12.3.0

Weakness classification (CWE)

CWE-789

References

github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst (Release Notes)
github.com/python-pillow/Pillow/commit/0a263e6264aa5399988d9acd3bbfbca2ca3ec77d (Patch)
github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x (Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-54059?: CVE-2026-54059 is a high-severity vulnerability in Python Pillow, classified under CWE-789. CVSS score: 7.5/10. Published 2026-07-06.
How severe is CVE-2026-54059?: High severity. CVSS v3 base score is 7.5 out of 10.