CVE-2026-112396: Pillow is a Python imaging library

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MEDIUM 5.9REMOTEUPGRADE

CVE-2026-112396 is a medium-severity flaw (CVSS 5.9) 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. From 11.3.0 until 13.0.0, Pillow has a heap use-after-free when libtiff rejects a tag while encoding TIFF data to an in-memory buffer. When an application saves attacker-influenced TIFF tags to BytesIO, libtiff can reject a tag during encoding in ImagingLibTiffEncode; the error path then frees the output buffer without closing or clearing the TIFF handle, and later cleanup flushes through the write callback int

Why this priority

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

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-416
Published	2026-10-19
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

2026-10-19 22:17 UTCPublished CVE record published
2026-10-26 21:00 UTCUpdated Record last modified

python pillow UPGRADE

Affected: >= 11.3.0 and < 13.0.0

Fixed in: 13.0.0

Safe to downgrade to: a release before 11.3.0

1. Check installed version

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

2. UPGRADE to 13.0.0 (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 11.3.0 (Debian / Ubuntu)

apt-cache madison pillow sudo apt install pillow=<VERSION_BEFORE_11.3.0> 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_11.3.0> 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-2026-112396?

pillow: upgrade to 13.0.0. Exact commands for each OS are on this page.

Is CVE-2026-112396 being exploited?

CVE-2026-112396 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-2026-112396 affect?

CVE-2026-112396 affects pillow. Severity is medium (CVSS 5.9). Pillow is a Python imaging library. From 11.3.0 until 13.0.0, Pillow has a heap use-after-free when libtiff rejects a tag while encoding TIFF data to an in-memory buffer. When an application saves attacker-influenced TIFF tags to BytesIO, l

How urgent is CVE-2026-112396?

Priority 43/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-40192 HIGH 7.5 UPGRADE Pillow is a Python imaging library
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-2026-112392 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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