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TI-2026-79973 Aliases CVE-2026-115585GHSA-jr96-gvgh-j3r4

Incomplete fix leaves pypdf slow on malformed cross-reference entries

Priority LOW 31CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 7 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.

Summary

pypdf before 6.21.2 is a pure-Python PDF library whose earlier fix for repeated malformed cross-reference entries was incomplete. A crafted cross-reference stream can still force a full stream reload on each recovery attempt, even when a recovery cache is present (CWE-407). If a user opens a crafted PDF file, the library can run for a long time, which causes a denial of service.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.2, an incomplete remediation for repeated malformed cross-reference entries in GHSA-55h5-xmcq-c37v could still trigger a complete PDF stream reload during each recovery attempt even when a recovery cache was present, causing crafted cross-reference streams to produce long runtimes. This issue is fixed in version 6.21.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0041 35th percentileScored 2026-11-07
Fix Partial pypdf (py-pdf): 6.21.2pypdf (PyPI): 6.21.2Red Hat: 7 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

VendorProductAffected versionsFixed inStatusSource
py-pdfpypdfbefore 6.21.26.21.2Patch availableCNA
—pypdf (PyPI)before 6.21.26.21.2Patch availableGHSA-jr96-gvgh-j3r4
  • pypdf Vendorpy-pdf Affected before 6.21.2 Fixed in 6.21.2 Patch available CNA
  • pypdf (PyPI) Vendor— Affected before 6.21.2 Fixed in 6.21.2 Patch available GHSA-jr96-gvgh-j3r4

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:*——py-pdf
  • cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:* Versions — — ·py-pdf

Remediation

Upgrade pypdf on PyPI to version 6.21.2, the fixed version. For Red Hat products, the sources list no fixed version. Ansible Automation Orchestrator 2026, Lightspeed Core, OpenShift Lightspeed, Red Hat Enterprise Linux AI (RHEL AI) 3 and Red Hat OpenShift AI (RHOAI) are listed with no fix available, and Red Hat Ansible Automation Platform 2 and Red Hat Quay 3 with no fix planned.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA pypdf (py-pdf) Fixed in 6.21.2
  • Fix · GHSA-jr96-gvgh-j3r4 pypdf (PyPI) Fixed in 6.21.2 Advisory →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Ansible Automation Orchestrator 2026AffectedNo fix yet: Fix deferred
Lightspeed CoreAffectedNo fix yet: Fix deferred
OpenShift LightspeedAffectedNo fix yet: Fix deferred
Red Hat Ansible Automation Platform 2AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred
Red Hat Quay 3AffectedNo fix planned: Out of support scope

Timeline

  1. 2026-10-23 Threatist record created from CVE-2026-115585
  2. 2026-10-23 Alias added: GHSA-jr96-gvgh-j3r4
  3. 2026-10-23 Fix available: PyPI/[email protected] · GHSA-jr96-gvgh-j3r4
  4. 2026-10-23 CVSS score added · GHSA-jr96-gvgh-j3r4
  5. 2026-10-23 Weakness changed · GHSA-jr96-gvgh-j3r4
  6. 2026-10-23 5 new references · GHSA-jr96-gvgh-j3r4
  7. 2026-10-24 Priority changed: MEDIUM → LOW
  8. 2026-10-24 Affected versions changed · Red Hat
  9. 2026-10-24 CVSS score added · Red Hat
  10. 2026-10-30 CISA SSVC decision points changed

References

Other 5

  • TI-2026-79334 Exponential SVG use expansion exhausts CPU and memory in fpdf2 CVSS 3.1MEDIUM 6.5
  • 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-2022-08670 Manipulated inline images can cause Infinite Loop in PyPDF2 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
See all 73 →

Sources

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