TI-2026-19910 Aliases CVE-2026-24688 GHSA-2q4j-m29v-hq73

pypdf has possible Infinite Loop when processing outlines/bookmarks

LOW 24CWE-835Published 2026-01-27 · Updated 2026-01-27

Key facts

Attack vector: Local
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · Low
Fix status: Partial Red Hat: 4 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-835.

Summary

pypdf is a free and open-source pure-python PDF library. An attacker who uses an infinite loop vulnerability that is present in versions prior to 6.6.2 can craft a PDF which leads to an infinite loop. This requires accessing the outlines/bookmarks. This has been fixed in pypdf 6.6.2. If projects cannot upgrade yet, consider applying the changes from PR #3610 manually.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00445 38th percentileScored 2026-11-07

Fix Partial pypdf (py-pdf): 6.6.2pypdf (PyPI): 6.6.2Red Hat: 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
py-pdf	pypdf	before 6.6.2	6.6.2	Patch available	CNA
—	pypdf (PyPI)	before 6.6.2	6.6.2	Patch available	GHSA-2q4j-m29v-hq73

pypdf Vendorpy-pdf Affected before 6.6.2 Fixed in 6.6.2 Patch available CNA
pypdf (PyPI) Vendor— Affected before 6.6.2 Fixed in 6.6.2 Patch available GHSA-2q4j-m29v-hq73

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:py-pdf:pypdf::::::::	before 6.6.2	Vulnerable	py-pdf

cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:* Versions before 6.6.2 Vulnerable ·py-pdf

Remediation

Fix · CNA pypdf (py-pdf) Fixed in 6.6.2
Fix · GHSA-2q4j-m29v-hq73 pypdf (PyPI) Fixed in 6.6.2 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
OpenShift Lightspeed	Affected	No fix yet: Fix deferred
Red Hat Ansible Automation Platform 2	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3	Affected	No fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-24688
2026-10-03 Alias added: GHSA-2q4j-m29v-hq73

References

Patch 1

https://github.com/py-pdf/pypdf/commit/b1282f8dcdc1a7b41ceab6740ffddfdf31b1fec1

Advisory 2

Other 3

TI-2023-18601 Infinite Loop when reading malformed objects in pypdf CVSS 3.1MEDIUM 6.5
TI-2023-18305 Infinite Loop when a comment isn't followed by a character in pypdf CVSS 3.1MEDIUM 6.2
TI-2026-42743 pypdf: Possible infinite loop for not terminated inline images CVSS 4.0HIGH 8.7
TI-2026-42742 pypdf: Possible infinite loop for not terminated inline images (ASCII85 and ASCIIHex filter) CVSS 4.0HIGH 8.7
TI-2026-65557 pypdf: Possible large memory usage when retrieving alphabetical page labels CVSS 4.0HIGH 8.7
TI-2026-65556 pypdf: Possible long runtimes with large amount of embedded files CVSS 4.0HIGH 8.7

See all 65 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences