CVE-2026-55798: Pillow is a Python imaging library

Q: How do I fix CVE-2026-55798?

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

Q: Is CVE-2026-55798 being exploited?

CVE-2026-55798 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-2026-55798 affect?

CVE-2026-55798 affects pillow. Severity is medium (CVSS 4.5). Pillow is a Python imaging library. Prior to 12.3.0, WindowsViewer.get_command() constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=Tr

Q: How urgent is CVE-2026-55798?

Priority 23/100. Public exploit reference

Routine

MEDIUM 4.5UPGRADE

CVE-2026-55798 is a medium-severity flaw (CVSS 4.5) 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, WindowsViewer.get_command() constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=True), allowing shell metacharacters in the file path to inject arbitrary cmd.exe commands. This issue is fixed in version 12.3.0.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.5 (Medium)
Attack vector	Local
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 93%)
CISA exploited list	No
Weakness	CWE-78
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-2026-55798?

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

Is CVE-2026-55798 being exploited?

CVE-2026-55798 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-2026-55798 affect?

CVE-2026-55798 affects pillow. Severity is medium (CVSS 4.5). Pillow is a Python imaging library. Prior to 12.3.0, WindowsViewer.get_command() constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=Tr

How urgent is CVE-2026-55798?

Priority 23/100. Public exploit reference

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-55379 HIGH 7.5 UPGRADE Pillow is a Python imaging library
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-2026-54058 CRITICAL 9.1 UPGRADE Pillow is a Python imaging library

References

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