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
CVE-2026-54059 is a high-severity vulnerability in the Pillow Python imaging library. The flaw exists in the _load_bitmaps() function of PIL/PcfFontFile.py, which reads glyph dimensions from the PCF METRICS section and passes them directly to Image.frombytes() without invoking Image._decompression_bomb_check(). This omission allows an attacker to craft PCF font data that triggers excessive memory allocation, potentially leading to denial of service due to resource exhaustion. The vulnerability affects all Pillow versions prior to 12.3.0 and is addressed by adding the decompression bomb check in version 12.3.0.
Potential Impact
The vulnerability can cause excessive memory allocation when processing maliciously crafted PCF font data, leading to denial of service conditions. There is no impact on confidentiality or integrity reported. The CVSS 3.1 base score is 7.5 (high), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and impact limited to availability.
Mitigation Recommendations
This issue is fixed in Pillow version 12.3.0. Users should upgrade to version 12.3.0 or later to remediate this vulnerability. No other mitigation or temporary workaround is indicated in the available data.
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
CVE-2026-54059 is a high-severity vulnerability in the Pillow Python imaging library. The flaw exists in the _load_bitmaps() function of PIL/PcfFontFile.py, which reads glyph dimensions from the PCF METRICS section and passes them directly to Image.frombytes() without invoking Image._decompression_bomb_check(). This omission allows an attacker to craft PCF font data that triggers excessive memory allocation, potentially leading to denial of service due to resource exhaustion. The vulnerability affects all Pillow versions prior to 12.3.0 and is addressed by adding the decompression bomb check in version 12.3.0.
Potential Impact
The vulnerability can cause excessive memory allocation when processing maliciously crafted PCF font data, leading to denial of service conditions. There is no impact on confidentiality or integrity reported. The CVSS 3.1 base score is 7.5 (high), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and impact limited to availability.
Mitigation Recommendations
This issue is fixed in Pillow version 12.3.0. Users should upgrade to version 12.3.0 or later to remediate this vulnerability. No other mitigation or temporary workaround is indicated in the available data.
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: 07/06/2026, 19:21:42 UTC
Last updated: 07/07/2026, 01:47:44 UTC
Views: 13
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