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.
INFO
Published Date :
July 6, 2026, 7:17 p.m.
Last Modified :
July 7, 2026, 6:58 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Pillow to version 12.3.0 or later.
- Apply security patches from the vendor.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54059.
| URL | Resource |
|---|---|
| https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst | Release Notes |
| https://github.com/python-pillow/Pillow/commit/0a263e6264aa5399988d9acd3bbfbca2ca3ec77d | Patch |
| https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x | Exploit Vendor Advisory |
| https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54059 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54059
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54059 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54059 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 07, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* versions up to (excluding) 12.3.0 Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/commit/0a263e6264aa5399988d9acd3bbfbca2ca3ec77d Types: Patch Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 07, 2026
Action Type Old Value New Value Added Reference https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x Added SSVC {'id': 'CVE-2026-54059', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-07T16:44:18.151665Z'} -
New CVE Received by [email protected]
Jul. 06, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'python-pillow', 'product': 'Pillow', 'versions': [{'status': 'affected', 'version': '< 12.3.0'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-789 Added Reference https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst Added Reference https://github.com/python-pillow/Pillow/commit/0a263e6264aa5399988d9acd3bbfbca2ca3ec77d Added Reference https://github.com/python-pillow/Pillow/security/advisories/GHSA-8v84-f9pq-wr9x