Vulnerability · Published Jul 6, 2026 · Assigned by GitHub_M
CVE-2026-55379Pillow BdfFontFile`: `Image.new()` called without `_decompression_bomb_check()` — bomb protection bypass via font loading
High 7.5
In plain English
A high-severity security flaw in Pillow from python-pillow. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | python3-pillow | 5.1.1-22.el8_10 | ALSA-2026:39127 |
| AlmaLinux:8 | python3-pillow-devel | 5.1.1-22.el8_10 | ALSA-2026:39127 |
| AlmaLinux:8 | python3-pillow-doc | 5.1.1-22.el8_10 | ALSA-2026:39127 |
| AlmaLinux:8 | python3-pillow-tk | 5.1.1-22.el8_10 | ALSA-2026:39127 |
| Debian:12 | pillow | no fix listed | DEBIAN-CVE-2026-55379 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-55379 |
| Debian:14 | pillow | 12.3.0-1 | DEBIAN-CVE-2026-55379 |
| PyPI | pillow | 12.3.0 | GHSA-45hq-cxwh-f6vc |
| PyPI | pillow | 12.3.0 | PYSEC-2026-2255 |
| Rocky Linux:8 | python-pillow | 0:5.1.1-22.el8_10 | RLSA-2026:39127 |
| Ubuntu:22.04:LTS | pillow | 9.0.1-1ubuntu0.6 | USN-8999-1 |
| Ubuntu:22.04:LTS | pillow | 9.0.1-1ubuntu0.6 | UBUNTU-CVE-2026-55379 |
| Ubuntu:24.04:LTS | pillow | 10.2.0-1ubuntu1.4 | USN-8999-1 |
| Ubuntu:24.04:LTS | pillow | 10.2.0-1ubuntu1.4 | UBUNTU-CVE-2026-55379 |
| Ubuntu:26.04:LTS | pillow | 12.1.1-2ubuntu1.4 | USN-8999-1 |
| Ubuntu:26.04:LTS | pillow | 12.1.1-2ubuntu1.4 | UBUNTU-CVE-2026-55379 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | < 12.3.0 |
Weakness: CWE-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H