How severe is GHSA-fwg2-594c-jp42?

No CVSS score has been assigned to GHSA-fwg2-594c-jp42 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-fwg2-594c-jp42?

GHSA-fwg2-594c-jp42 affects the following packages: pypdf (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-fwg2-594c-jp42?

Update pypdf to 6.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fwg2-594c-jp42 is resolved across your whole dependency graph.

How do I detect GHSA-fwg2-594c-jp42 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 GHSA-fwg2-594c-jp42 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 GHSA-fwg2-594c-jp42 actively exploited in the wild?

No public exploit code has been indexed for GHSA-fwg2-594c-jp42 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 GHSA-fwg2-594c-jp42?

GHSA-fwg2-594c-jp42 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 7th 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 GHSA-fwg2-594c-jp42?

GHSA-fwg2-594c-jp42 is classified as CWE-834 (CWE-834). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-fwg2-594c-jp42 published, and has it been updated?

GHSA-fwg2-594c-jp42 was published on August 7, 2026 and was last updated on September 10, 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

GHSA-fwg2-594c-jp42 — pypdf

Fix: py-pdf/pypdf#3946

GHSA-fwg2-594c-jp42 is a CWE-834 vulnerability in pypdf. A fix is available for pypdf — see the affected versions and patch details below.

pypdf: Possible long runtimes/large memory usage for large CID font width ranges

Also known asCVE-2026-71852PYSEC-2026-3656

Published

Aug 7, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 26, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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 GHSA-fwg2-594c-jp42.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs7th percentile — riskier than 7% 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 long runtimes and large memory consumption. This requires parsing the font width entries of a font with unusually large values, for example during text extraction.

Patches

This has been fixed in pypdf==6.15.0.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3946.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`pypdf`	all versions	6.15.0`pip install --upgrade 'pypdf==6.15.0'`

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 6.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fwg2-594c-jp42 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 HatModerate

This Moderate impact denial-of-service vulnerability in the pypdf library can lead to excessive memory consumption and long runtimes when processing specially crafted PDF files. This issue affects Red Hat products that handle untrusted PDF input, potentially causing service disruption due to resource exhaustion.…

Workaround published by Red Hat

To reduce exposure, avoid processing untrusted PDF documents with applications that integrate the pypdf library. Implement robust input validation and sanitization for all PDF files originating from external or unverified sources. Consider deploying applications that process PDF content within a sandboxed environment to contain potential denial of service impacts.

Source: Red Hat security advisory for GHSA-fwg2-594c-jp42 (CC BY 4.0)

Frequently Asked Questions

### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires parsing the font width entries of a font with unusually large values, for example during text extraction. ### Patches This has been fixed in [pypdf==6.15.0](https://github.com/py-pdf/pypdf/releases/tag/6.15.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3946](https://github.com/py-pdf/pypdf/pull/3946).

O3 Security · Impact-Aware SCA

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