How severe is CVE-2026-113786?

No CVSS score has been assigned to CVE-2026-113786 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-113786?

CVE-2026-113786 affects the following packages: pypdf (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-113786?

Update pypdf to 6.21.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-113786 is resolved across your whole dependency graph.

How do I detect CVE-2026-113786 in my PyPI dependencies?

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

How do I mitigate CVE-2026-113786 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-2026-113786 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-113786 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-2026-113786?

CVE-2026-113786 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-2026-113786?

CVE-2026-113786 is classified as Improper Input Validation (CWE-20), CWE-183 (CWE-183). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-113786 published, and has it been updated?

CVE-2026-113786 was published on October 21, 2026 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2026-113786 — pypdf

Fix: py-pdf/pypdf@512d8eb

CVE-2026-113786 is a Improper Input Validation vulnerability in pypdf. A fix is available for pypdf — see the affected versions and patch details below.

pypdf: Unvalidated JPEG image data loading

Also known asGHSA-5hx5-vpf9-5wcv

Published

Oct 21, 2026

Updated

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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

🐍pypdf

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

Impact

An attacker who uses this vulnerability can craft a PDF which leads to arbitrary image parsers being called. This requires loading an image which claims to use the /DCTDecode filter (JPEG data).

Users which do not have the optional Pillow dependency installed in their environment are not affected.

Patches

This has been fixed in pypdf==6.21.1.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #4222.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`pypdf`	all versions	6.21.1`pip install --upgrade 'pypdf==6.21.1'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pypdf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pypdf to 6.21.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-113786 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.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatLow

This vulnerability is rated Low impact because exploitation is limited to a localized denial of service during document parsing, requiring an attacker to supply a specially crafted file to an environment with the optional Pillow image library active. In Red Hat environments such as OpenShift AI, Lightspeed, and Quay,…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Source: Red Hat security advisory for CVE-2026-113786 (CC BY 4.0)

Frequently Asked Questions

### Impact An attacker who uses this vulnerability can craft a PDF which leads to arbitrary image parsers being called. This requires loading an image which claims to use the `/DCTDecode` filter (JPEG data). Users which do not have the optional *Pillow* dependency installed in their environment are not affected. ### Patches This has been fixed in [pypdf==6.21.1](https://github.com/py-pdf/pypdf/releases/tag/6.21.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#4222](https://github.com/py-pdf/pypdf/pull/4222).

O3 Security · Impact-Aware SCA

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