CVE-2026-54059: CWE-789: Memory Allocation with Excessive Size Value in python-pillow Pillow
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.
AI Analysis
Technical Summary
The Pillow Python imaging library contains a memory allocation vulnerability (CWE-789) in the _load_bitmaps() function of PIL/PcfFontFile.py. Prior to version 12.3.0, this function reads glyph dimensions from the PCF METRICS section and passes them directly to Image.frombytes() without invoking Image._decompression_bomb_check(). This omission allows specially crafted PCF font data to trigger excessive memory allocation, potentially leading to denial of service. The vulnerability is addressed in Pillow version 12.3.0.
Potential Impact
Exploitation of this vulnerability can cause excessive memory allocation, leading to denial of service conditions. There is no indication of confidentiality or integrity impact. The CVSS 3.1 base score is 7.5 (high severity) with network attack vector, low attack complexity, no privileges or user interaction required, and impact limited to availability.
Mitigation Recommendations
Upgrade to Pillow version 12.3.0 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in version 12.3.0, applying this official update fully mitigates the issue. No other mitigations are indicated.
CVE-2026-54059: CWE-789: Memory Allocation with Excessive Size Value in python-pillow Pillow
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.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Pillow Python imaging library contains a memory allocation vulnerability (CWE-789) in the _load_bitmaps() function of PIL/PcfFontFile.py. Prior to version 12.3.0, this function reads glyph dimensions from the PCF METRICS section and passes them directly to Image.frombytes() without invoking Image._decompression_bomb_check(). This omission allows specially crafted PCF font data to trigger excessive memory allocation, potentially leading to denial of service. The vulnerability is addressed in Pillow version 12.3.0.
Potential Impact
Exploitation of this vulnerability can cause excessive memory allocation, leading to denial of service conditions. There is no indication of confidentiality or integrity impact. The CVSS 3.1 base score is 7.5 (high severity) with network attack vector, low attack complexity, no privileges or user interaction required, and impact limited to availability.
Mitigation Recommendations
Upgrade to Pillow version 12.3.0 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in version 12.3.0, applying this official update fully mitigates the issue. No other mitigations are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-11T18:24:35.096Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4bfce927e9c7971910b4b6
Added to database: 07/06/2026, 19:07:21 UTC
Last enriched: 07/14/2026, 08:54:16 UTC
Last updated: 08/18/2026, 10:56:13 UTC
Views: 86
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