CVE-2026-40192: Pillow is a Python imaging library

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HIGH 7.5REMOTEUPGRADE

CVE-2026-40192 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. Versions 10.3.0 through 12.1.1 did not limit the amount of GZIP-compressed data read when decoding a FITS image, making them vulnerable to decompression bomb attacks. A specially crafted FITS file could cause unbounded memory consumption, leading to denial of service (OOM crash or severe performance degradation). If users are unable to immediately upgrade, they should only open specific image formats, excluding

Why this priority

High severity
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	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-400, CWE-770, CWE-409
Published	2026-04-15
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-15 23:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

python pillow UPGRADE

Affected: >= 10.3.0 and < 12.2.0

Fixed in: 12.2.0

Safe to downgrade to: a release before 10.3.0

1. Check installed version

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

2. UPGRADE to 12.2.0 (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.

3. If no update is available yet, DOWNGRADE to a release before 10.3.0 (Debian / Ubuntu)

apt-cache madison pillow sudo apt install pillow=<VERSION_BEFORE_10.3.0> sudo apt-mark hold pillow

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pillow sudo dnf downgrade pillow-<VERSION_BEFORE_10.3.0> sudo dnf versionlock add pillow

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-40192?

pillow: upgrade to 12.2.0. Exact commands for each OS are on this page.

Is CVE-2026-40192 being exploited?

CVE-2026-40192 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-2026-40192 affect?

CVE-2026-40192 affects pillow. Severity is high (CVSS 7.5). Pillow is a Python imaging library. Versions 10.3.0 through 12.1.1 did not limit the amount of GZIP-compressed data read when decoding a FITS image, making them vulnerable to decompression bomb attacks. A specially crafted FITS file could c

How urgent is CVE-2026-40192?

Priority 44/100. High severity; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-112393 CRITICAL 9.8 UPGRADE Pillow is a Python imaging library
CVE-2026-112394 HIGH 8.2 UPGRADE Pillow is a Python imaging library
CVE-2026-112396 MEDIUM 5.9 UPGRADE Pillow is a Python imaging library
CVE-2026-112392 HIGH 7.5 UPGRADE Pillow is a Python imaging library
CVE-2026-112395 MEDIUM 6.5 UPGRADE Pillow is a Python imaging library

References

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