CVE-2026-55379: Pillow is a Python imaging library

Q: How do I fix CVE-2026-55379?

pillow: upgrade to 12.3.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-55379 being exploited?

CVE-2026-55379 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-55379 affect?

CVE-2026-55379 affects pillow. Severity is high (CVSS 7.5). 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_c

Q: How urgent is CVE-2026-55379?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-55379 is a high-severity flaw (CVSS 7.5) affecting pillow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 56%)
CISA exploited list	No
Weakness	CWE-789
Published	2026-07-06
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: python

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-06 19:17 UTCPublished CVE record published
2026-10-25 20:10 UTCUpdated Record last modified

python pillow UPGRADE

Affected: < 12.3.0

Fixed in: 12.3.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy pillow || rpm -q pillow || pillow --version

2. UPGRADE to 12.3.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade pillow

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pillow

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-55379?

pillow: upgrade to 12.3.0. Exact commands for each OS are on this page.

Is CVE-2026-55379 being exploited?

CVE-2026-55379 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-55379 affect?

CVE-2026-55379 affects pillow. Severity is high (CVSS 7.5). 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_c

How urgent is CVE-2026-55379?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-55380 HIGH 7.5 UPGRADE Pillow is a Python imaging library
CVE-2026-54059 HIGH 7.5 UPGRADE Pillow is a Python imaging library
CVE-2026-54060 HIGH 7.5 UPGRADE Pillow is a Python imaging library
CVE-2026-55798 MEDIUM 4.5 UPGRADE Pillow is a Python imaging library
CVE-2026-54058 CRITICAL 9.1 UPGRADE Pillow is a Python imaging library

References

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