TI-2026-57946 Aliases CVE-2026-84311 GHSA-763m-79hh-57f2

pypdf: Possible long runtimes/large memory usage when extracting XForm objects

LOW 21CWE-834Published 2026-09-01 · Updated 2026-09-02

Key facts

Attack vector: Local
Privileges required: None
User interaction: Passive
Attack complexity: Low
Attack requirements: None
Impact type: —
Confidentiality · integrity · availability: None · None · Low
Fix status: Partial Red Hat: 8 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00135 2nd percentileScored 2026-11-07

Fix Partial pypdf (py-pdf): 6.16.1pypdf (PyPI): 6.16.1Red Hat: 8 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 6.16.1	6.16.1	Patch available	CNA
—	pypdf (PyPI)	before 6.16.1	6.16.1	Patch available	GHSA-763m-79hh-57f2

pypdf Vendorpy-pdf Affected before 6.16.1 Fixed in 6.16.1 Patch available CNA
pypdf (PyPI) Vendor— Affected before 6.16.1 Fixed in 6.16.1 Patch available GHSA-763m-79hh-57f2

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:py-pdf:pypdf::::::::	before 6.16.1	Vulnerable	py-pdf

cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:* Versions before 6.16.1 Vulnerable ·py-pdf

Remediation

Fix · CNA pypdf (py-pdf) Fixed in 6.16.1
Fix · GHSA-763m-79hh-57f2 pypdf (PyPI) Fixed in 6.16.1 Advisory →

Vendor assessments

Red Hat

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

Product	Status	Plan or fix
Ansible Automation Orchestrator 2026	Affected	No fix yet: Fix deferred
Exploit Intelligence	Affected	No fix planned: Out of support scope
Lightspeed Core	Affected	No fix yet: Fix deferred
OpenShift Lightspeed	Affected	No fix yet: Fix deferred
Red Hat Ansible Automation Platform 2	Affected	No fix planned: Out of support scope
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
Red Hat Quay 3	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-84311
2026-10-03 Alias added: GHSA-763m-79hh-57f2
2026-10-05 CVSS score added · NVD

References

Patch 3

Other 2

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