How severe is GHSA-w23x-9jrw-r45c?

No CVSS score has been assigned to GHSA-w23x-9jrw-r45c yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-w23x-9jrw-r45c?

GHSA-w23x-9jrw-r45c affects the following packages: pypdf (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-w23x-9jrw-r45c?

Update pypdf to 6.19.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w23x-9jrw-r45c is resolved across your whole dependency graph.

How do I detect GHSA-w23x-9jrw-r45c 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-w23x-9jrw-r45c if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is GHSA-w23x-9jrw-r45c actively exploited in the wild?

No public exploit code has been indexed for GHSA-w23x-9jrw-r45c 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-w23x-9jrw-r45c?

GHSA-w23x-9jrw-r45c has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 21th 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-w23x-9jrw-r45c?

GHSA-w23x-9jrw-r45c is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-w23x-9jrw-r45c published, and has it been updated?

GHSA-w23x-9jrw-r45c was published on October 1, 2026 and was last updated on October 1, 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-w23x-9jrw-r45c — pypdf

Fix: py-pdf/pypdf#4096

GHSA-w23x-9jrw-r45c is a Uncontrolled Resource Consumption vulnerability in pypdf. A fix is available for pypdf — see the affected versions and patch details below.

pypdf: Possible large memory usage when retrieving alphabetical page labels

Also known asCVE-2026-103000PYSEC-2026-4160

Published

Oct 1, 2026

Updated

Oct 1, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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 GHSA-w23x-9jrw-r45c.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs21th percentile — riskier than 21% 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 large memory consumption. This requires accessing the page labels of a document with large alphabetical labels.

Patches

This has been fixed in pypdf==6.19.0.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #4096.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`pypdf`	all versions	6.19.0`pip install --upgrade 'pypdf==6.19.0'`

Affected Products

1 product · 1 configurations

Application

pypdfpypdf_project

< 6.19.0

range

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 6.19.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w23x-9jrw-r45c is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

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 HatImportant

This Important impact flaw can exhaust memory when a Red Hat product retrieves page labels from a crafted PDF containing unusually large alphabetical label values.

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 GHSA-w23x-9jrw-r45c (CC BY 4.0)

Frequently Asked Questions

### Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory consumption. This requires accessing the page labels of a document with large alphabetical labels. ### Patches This has been fixed in [pypdf==6.19.0](https://github.com/py-pdf/pypdf/releases/tag/6.19.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#4096](https://github.com/py-pdf/pypdf/pull/4096).

O3 Security · Impact-Aware SCA

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