How severe is CVE-2026-112891?

No CVSS score has been assigned to CVE-2026-112891 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-112891?

CVE-2026-112891 affects the following packages: pillow (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-112891?

Update pillow to 13.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-112891 is resolved across your whole dependency graph.

How do I detect CVE-2026-112891 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pillow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-112891 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-112891 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-112891 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-112891?

CVE-2026-112891 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 30th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-112891?

CVE-2026-112891 is classified as CWE-407 (CWE-407). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-112891 published, and has it been updated?

CVE-2026-112891 was published on October 19, 2026 and was last updated on October 23, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-112891: pillow — Fixed in 13.0.0

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-112891.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs30th percentile — riskier than 30% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐍pillow

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Pillow is a Python imaging library. From 9.2.0 until 13.0.0, Pillow performs quadratic copying when saving a GIF with a long comment. _get_global_header() repeatedly copies portions of comment data while assembling the global header, including comments retained from an untrusted input image. An attacker can supply an image with a large GIF comment to an application that saves it as GIF. This can consume excessive CPU and delay or deny service. This issue is fixed in version 13.0.0.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`pillow`	≥ 9.2.0&&< 13.0.0	13.0.0`pip install --upgrade 'pillow==13.0.0'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pillow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pillow to 13.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-112891 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

Pillow is a Python imaging library. From 9.2.0 until 13.0.0, Pillow performs quadratic copying when saving a GIF with a long comment. _get_global_header() repeatedly copies portions of comment data while assembling the global header, including comments retained from an untrusted input image. An attacker can supply an image with a large GIF comment to an application that saves it as GIF. This can consume excessive CPU and delay or deny service. This issue is fixed in version 13.0.0.

O3 Security · Impact-Aware SCA

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CVE-2026-112891 — pillow