Is CVE-2026-22691 in the CISA KEV catalog?

No. CVE-2026-22691 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-22691?

CVE-2026-22691 has a CVSS v3 base score of 5.3 (MEDIUM).

What is the EPSS score for CVE-2026-22691?

CVE-2026-22691 has an EPSS score of 0.39% (31th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-22691?

Upgrade pypdf on debian unstable to 6.9.0-1 or later.

CVE & CISA-KEV Catalog

CVE-2026-22691

MEDIUM

5.3

CVSS v3

NVD

Description

pypdf is a free and open-source pure-python PDF library. Prior to version 6.6.0, pypdf has possible long runtimes for malformed startxref. An attacker who uses this vulnerability can craft a PDF which leads to possibly long runtimes for invalid startxref entries. When rebuilding the cross-reference table, PDF files with lots of whitespace characters become problematic. Only the non-strict reading mode is affected. Only the non-strict reading mode is affected. This issue has been patched in version 6.6.0.

CWE-400Resource Exhaustion CWE-1333

How to fix

Remediation Available

pypdfDebian

Fixed in:6.9.0-1CVE-2026-22691

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityLow

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Exploit Intelligence

0.39%probability of exploitation in 30 days

31stpercentile

Low risk: more likely to be exploited than 31% of all known CVEs.

References

Patch2

Vendor Advisory1

github.com

Release Notes1

github.com

Related Vulnerabilities

Other CWE-400 (Resource Exhaustion) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-44487	High	7.5	100%	KEV	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2011-3192	High	7.8	99%	-	Fix
CVE-2019-11478	Medium	5.3	95%	-	Fix
CVE-2024-25617	Medium	5.3	89%	-	Fix
CVE-2018-1000115	High	7.5	89%	-	Fix

Embed a live status badge for CVE-2026-22691

Markdown

[![CVE-2026-22691](https://tridentstack.com/cve/badge/CVE-2026-22691.svg)](https://tridentstack.com/cve/CVE-2026-22691)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-22691"><img src="https://tridentstack.com/cve/badge/CVE-2026-22691.svg" alt="CVE-2026-22691"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-01-22.