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TI-2026-78808 Aliases CVE-2026-113786GHSA-5hx5-vpf9-5wcv

pypdf loads unintended image parser from crafted JPEG data

Priority LOW 12CWE-183Published · Updated

Key facts

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

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

Summary

pypdf before 6.21.1 is affected. Image data labeled with the /DCTDecode filter is loaded without proper validation, so Pillow can select and invoke an unintended image parser (CWE-20). A remote attacker who crafts a PDF can trigger this when a user processes the file, and the issue has a low availability impact. Environments without the optional Pillow dependency are not affected.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.1, an attacker can craft a PDF containing image data labeled with the /DCTDecode filter that causes Pillow to select and invoke an unintended image parser when the image is loaded. Environments without the optional Pillow dependency are not affected. This issue is fixed in version 6.21.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00405 34th percentileScored 2026-11-07
Fix Partial pypdf (py-pdf): 6.21.1pypdf (PyPI): 6.21.1Red 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 6.21.16.21.1Patch availableCNA
—pypdf (PyPI)before 6.21.16.21.1Patch availableGHSA-5hx5-vpf9-5wcv
  • pypdf Vendorpy-pdf Affected before 6.21.1 Fixed in 6.21.1 Patch available CNA
  • pypdf (PyPI) Vendor— Affected before 6.21.1 Fixed in 6.21.1 Patch available GHSA-5hx5-vpf9-5wcv

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 to version 6.21.1, which fixes the issue. The sources list no fixed version for Red Hat Ansible Automation Platform 2 and Red Hat Quay 3, where no fix is planned, or for Ansible Automation Orchestrator 2026, Lightspeed Core, OpenShift Lightspeed, Red Hat Enterprise Linux AI (RHEL AI) 3 and Red Hat OpenShift AI (RHOAI), where none is available.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA pypdf (py-pdf) Fixed in 6.21.1
  • Fix · GHSA-5hx5-vpf9-5wcv pypdf (PyPI) Fixed in 6.21.1 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Low. 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. 2026-10-21 Threatist record created from CVE-2026-113786
  2. 2026-10-21 Alias added: GHSA-5hx5-vpf9-5wcv
  3. 2026-10-21 Fix available: PyPI/[email protected] · GHSA-5hx5-vpf9-5wcv
  4. 2026-10-21 CVSS score added · GHSA-5hx5-vpf9-5wcv
  5. 2026-10-21 Weakness changed · GHSA-5hx5-vpf9-5wcv
  6. 2026-10-21 6 new references · GHSA-5hx5-vpf9-5wcv
  7. 2026-10-22 Affected versions changed · Red Hat
  8. 2026-10-22 CVSS score added · Red Hat
  9. 2026-10-27 CISA SSVC decision points changed

References

Advisory 1

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