CVE-2026-55379: CWE-789: Memory Allocation with Excessive Size Value in python-pillow Pillow
Pillow is a Python imaging library. Prior to 12.3.0, PIL/BdfFontFile.py bdf_char() read the BBX width and height field from a BDF font file and passed attacker-controlled dimensions to Image.new() without calling Image._decompression_bomb_check(), bypassing Pillow's documented decompression bomb protection and allowing excessive memory allocation. This issue is fixed in version 12.3.0.
AI Analysis
Technical Summary
CVE-2026-55379 is a high-severity vulnerability in the python-pillow Pillow library affecting versions prior to 12.3.0. The vulnerability arises because the bdf_char() function in PIL/BdfFontFile.py reads the BBX width and height fields from a BDF font file and passes these attacker-controlled dimensions directly to Image.new() without calling Image._decompression_bomb_check(). This bypasses Pillow's decompression bomb protection mechanism, potentially allowing an attacker to cause excessive memory allocation. 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 due to resource exhaustion. There is no indication of confidentiality or integrity impact. The CVSS score is 7.5 (high), reflecting the potential for availability impact without requiring privileges or user interaction.
Mitigation Recommendations
Upgrade to Pillow version 12.3.0 or later, where this issue is fixed. No other mitigation is indicated or necessary as the vulnerability is resolved by this official fix.
CVE-2026-55379: 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/BdfFontFile.py bdf_char() read the BBX width and height field from a BDF font file and passed attacker-controlled dimensions to Image.new() without calling Image._decompression_bomb_check(), bypassing Pillow's documented decompression bomb protection and allowing 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-2026-55379 is a high-severity vulnerability in the python-pillow Pillow library affecting versions prior to 12.3.0. The vulnerability arises because the bdf_char() function in PIL/BdfFontFile.py reads the BBX width and height fields from a BDF font file and passes these attacker-controlled dimensions directly to Image.new() without calling Image._decompression_bomb_check(). This bypasses Pillow's decompression bomb protection mechanism, potentially allowing an attacker to cause excessive memory allocation. 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 due to resource exhaustion. There is no indication of confidentiality or integrity impact. The CVSS score is 7.5 (high), reflecting the potential for availability impact without requiring privileges or user interaction.
Mitigation Recommendations
Upgrade to Pillow version 12.3.0 or later, where this issue is fixed. No other mitigation is indicated or necessary as the vulnerability is resolved by this official fix.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-16T18:57:40.181Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4bfce927e9c7971910b4c0
Added to database: 07/06/2026, 19:07:21 UTC
Last enriched: 07/06/2026, 19:21:31 UTC
Last updated: 07/06/2026, 19:52:08 UTC
Views: 5
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