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TI-2026-76599 Aliases CVE-2026-112399GHSA-5xm2-6676-qcp9

Excessive memory use in Pillow APNG handling enables denial of service

Priority HIGH 77CWE-789Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 8 fixed, 9 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-789.

Summary

Pillow, a Python imaging library, is affected from 8.1.0 before 13.0.0. Pillow allocates an APNG disposal background at full canvas size before its decompression-bomb check (CWE-789). An unauthenticated attacker can supply a crafted APNG with a small first frame and a very large declared canvas, so opening it with Image.open() can exhaust memory and deny service. A public exploit is linked in the references, but the flaw is not listed in CISA KEV.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

Pillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow can allocate an APNG disposal background at the full canvas size before applying the decompression-bomb check. A crafted APNG with a small first frame, a very large declared canvas, and background disposal or first-frame OP_PREVIOUS reaches PngImageFile._seek while Image.open() positions frame zero. The full-canvas allocation occurs inside Image.open() without requiring pixel loading or frame iteration. This can exhaust memory and deny service. This issue is fixed in version 13.0.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00529 45th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Pillow (python-pillow): 13.0.0Pillow (PyPI): 13.0.0Red Hat: 12 advisoriesRed Hat: 8 fixed, 9 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
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
python-pillowPillow8.1.0 to before 13.0.013.0.0Patch availableCNA
—Pillow (PyPI)8.1.0 to before 13.0.013.0.0Patch availableGHSA-5xm2-6676-qcp9
  • Pillow Vendorpython-pillow Affected 8.1.0 to before 13.0.0 Fixed in 13.0.0 Patch available CNA
  • Pillow (PyPI) Vendor— Affected 8.1.0 to before 13.0.0 Fixed in 13.0.0 Patch available GHSA-5xm2-6676-qcp9

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*8.1.0 to before 13.0.0Vulnerablepython-pillow
  • cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* Versions 8.1.0 to before 13.0.0 Vulnerable ·python-pillow

Remediation

Upgrade Pillow to version 13.0.0. Red Hat fixes it in Red Hat AI Inference Server 3.5 (RHSA-2026:94738, RHSA-2026:94721, RHSA-2026:94717, RHSA-2026:94715, RHSA-2026:94709, RHSA-2026:94702), Red Hat OpenShift AI 3.4 (RHSA-2026:92510) and 3.5 (RHSA-2026:94631), and Red Hat Satellite 6.16 for RHEL 8 and 9 (RHSA-2026:95655), 6.17 for RHEL 9 (RHSA-2026:95656), 6.18 for RHEL 9 (RHSA-2026:95657) and 6.19 for RHEL 9 (RHSA-2026:92861). Red Hat plans no fix for Red Hat Lightspeed Services for OCP. The sources list no fixed version for Red Hat Ansible Automation Platform 2, Red Hat Enterprise Linux AI 3, Red Hat OpenShift AI (RHOAI), Red Hat Quay 3, and other products.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA Pillow (python-pillow) Fixed in 13.0.0
  • Fix · GHSA-5xm2-6676-qcp9 Pillow (PyPI) Fixed in 13.0.0 Advisory →

Red Hat 12 advisories

  • RHSA-2026:95655 Released 2026-11-05 · Red Hat rating Critical
    Satellite 6.16 EUS security update
    • Red Hat Satellite 6.16 for RHEL 8 openvox-agent-8.32.0-1.el8sat, openvox-server-8.18.0-1.el8sat, python-brotli-1.2.1-1.el8pc +11
    • Red Hat Satellite 6.16 for RHEL 9 openvox-agent-8.32.0-1.el9sat, openvox-server-8.18.0-1.el9sat, python-brotli-1.2.1-1.el9pc +11
  • RHSA-2026:95657 Released 2026-11-05 · Red Hat rating Critical
    Satellite 6.18 security update
    • Red Hat Satellite 6.18 for RHEL 9 openvox-agent-8.32.0-1.el9sat, openvox-server-8.18.0-1.el9sat, python3.12-brotli-1.2.1-1.el9pc +4
  • RHSA-2026:95656 Released 2026-11-05 · Red Hat rating Critical
    Satellite 6.17 security update
    • Red Hat Satellite 6.17 for RHEL 9 openvox-agent-8.32.0-1.el9sat, openvox-server-8.18.0-1.el9sat, python-brotli-1.2.1-1.el9pc +9
Show 9 more Red Hat advisories
  • RHSA-2026:94738 Released 2026-11-03 · Red Hat rating Critical
    Red Hat AI Inference 3.5.3 (CUDA)
    • Red Hat AI Inference Server 3.5 registry.redhat.io/rhaii/vllm-cuda-rhel9
  • RHSA-2026:94721 Released 2026-11-03 · Red Hat rating Critical
    Red Hat AI Inference Tech Preview 3.5.3 (Gaudi)
    • Red Hat AI Inference Server 3.5 registry.redhat.io/rhaii/vllm-gaudi-rhel9
  • RHSA-2026:94717 Released 2026-11-03 · Red Hat rating Critical
    Red Hat AI Inference 3.5.3 (Spyre)
    • Red Hat AI Inference Server 3.5 registry.redhat.io/rhaii/vllm-spyre-rhel9
  • RHSA-2026:94715 Released 2026-11-03 · Red Hat rating Critical
    Red Hat AI Inference Model Optimization Tools 3.5.3 (CUDA)
    • Red Hat AI Inference Server 3.5 registry.redhat.io/rhaii/model-opt-cuda-rhel9
  • RHSA-2026:94709 Released 2026-11-03 · Red Hat rating Critical
    Red Hat AI Inference 3.5.3 (ROCm)
    • Red Hat AI Inference Server 3.5 registry.redhat.io/rhaii/vllm-rocm-rhel9
  • RHSA-2026:94702 Released 2026-11-03 · Red Hat rating Critical
    Red Hat AI Inference 3.5.3 (CPU)
    • Red Hat AI Inference Server 3.5 registry.redhat.io/rhaii/vllm-cpu-rhel9
  • RHSA-2026:94631 Released 2026-11-03 · Red Hat rating Critical
    GuideLLM 3.5.1
    • Red Hat OpenShift AI 3.5 registry.redhat.io/rhai/guidellm-rhel9
  • RHSA-2026:92861 Released 2026-10-29 · Red Hat rating Critical
    Satellite 6.19 security update
    • Red Hat Satellite 6.19 for RHEL 9 openvox-agent-8.31.1-1.el9sat, openvox-server-8.17.0-1.el9sat, python3.12-brotli-1.2.1-1.el9pc +6
  • RHSA-2026:92510 Released 2026-10-29 · Red Hat rating Critical
    RHOAI 3.4.6 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-cli-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +47

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Exploit IntelligenceAffectedNo fix yet
Lightspeed CoreAffectedNo fix yet
OpenShift LightspeedAffectedNo fix yet
Red Hat AI Inference ServerAffectedNo fix planned: Will not fix
Red Hat Ansible Automation Platform 2AffectedNo fix yet
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix yet
Red Hat Lightspeed Services for OCPAffectedNo fix planned: Will not fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat Quay 3AffectedNo fix yet
Red Hat AI Inference Server 3.5Fixed RHSA-2026:94702, RHSA-2026:94709, RHSA-2026:94715, RHSA-2026:94717, RHSA-2026:94721, RHSA-2026:94738
Red Hat OpenShift AI 3.4Fixed RHSA-2026:92510
Red Hat OpenShift AI 3.5Fixed RHSA-2026:94631
Red Hat Satellite 6.16 for RHEL 8Fixed RHSA-2026:95655
Red Hat Satellite 6.16 for RHEL 9Fixed RHSA-2026:95655
Red Hat Satellite 6.17 for RHEL 9Fixed RHSA-2026:95656
Red Hat Satellite 6.18 for RHEL 9Fixed RHSA-2026:95657
Red Hat Satellite 6.19 for RHEL 9Fixed RHSA-2026:92861
Not affected: 10 products
  • Red Hat AI Inference Server
  • Red Hat Ansible Automation Platform 2
  • Red Hat Enterprise Linux 8
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift AI 3.4
  • Red Hat Satellite 6.16 for RHEL 8
  • Red Hat Satellite 6.16 for RHEL 9
  • Red Hat Satellite 6.17 for RHEL 9
  • Red Hat Satellite 6.18 for RHEL 9
  • Red Hat Satellite 6.19 for RHEL 9

Timeline

  1. 2026-10-20 Threatist record created from CVE-2026-112399
  2. 2026-10-20 Affected versions changed · Red Hat
  3. 2026-10-20 CVSS score added · Red Hat
  4. 2026-10-21 Priority changed: MEDIUM → LOW
  5. 2026-10-21 Affected versions changed · Red Hat
  6. 2026-10-21 Alias added: GHSA-5xm2-6676-qcp9
  7. 2026-10-21 Fix available: PyPI/[email protected] · GHSA-5xm2-6676-qcp9
  8. 2026-10-21 CVSS score added · GHSA-5xm2-6676-qcp9
  9. 2026-10-21 Weakness changed · GHSA-5xm2-6676-qcp9
  10. 2026-10-21 5 new references · GHSA-5xm2-6676-qcp9
  11. 2026-10-27 CVSS score added · NVD
  12. 2026-10-28 CISA SSVC decision points changed
  13. 2026-10-28 Priority changed: LOW → HIGH
  14. 2026-10-30 Fix available: RHSA-2026:92510 · Red Hat
  15. 2026-10-30 Fix available: Red Hat OpenShift AI 3.4 · Red Hat
  16. 2026-10-30 Fix available: Red Hat Satellite 6.19 for RHEL 9 · Red Hat
  17. 2026-10-31 Fix available: RHSA-2026:92861 · Red Hat
  18. 2026-11-04 Fix available: RHSA-2026:94717 · Red Hat
  19. 2026-11-04 Fix available: RHSA-2026:94715 · Red Hat
  20. 2026-11-04 Fix available: RHSA-2026:94709 · Red Hat
  21. 2026-11-04 Fix available: RHSA-2026:94738 · Red Hat
  22. 2026-11-04 Fix available: RHSA-2026:94702 · Red Hat
  23. 2026-11-04 Fix available: RHSA-2026:94631 · Red Hat
  24. 2026-11-04 Fix available: RHSA-2026:94721 · Red Hat
  25. 2026-11-04 Fix available: Red Hat AI Inference Server 3.5, Red Hat OpenShift AI 3.5 · Red Hat
  26. 2026-11-05 Affected versions changed · Red Hat
  27. 2026-11-06 Fix available: Red Hat Satellite 6.16 for RHEL 8, Red Hat Satellite 6.16 for RHEL 9, Red Hat Satellite 6.17 for RHEL 9 +1 · Red Hat
  28. 2026-11-06 Fix available: RHSA-2026:95656 · Red Hat
  29. 2026-11-06 Fix available: RHSA-2026:95655 · Red Hat
  30. 2026-11-06 Fix available: RHSA-2026:95657 · Red Hat

References

Exploit 1

Patch 1

Advisory 1

Other 2

  • TI-2026-76627 Out-of-bounds read in Pillow TIFF encoder ColorMap handling CVSS 4.0HIGH 8.8
  • TI-2026-76625 Quadratic-time denial of service in Pillow PDF save_all CVSS 4.0HIGH 8.7
  • TI-2026-76605 NULL pointer dereference in Pillow's Image.merge function CVSS 4.0HIGH 8.7
  • TI-2026-76604 Out-of-bounds read in Pillow TIFF decoding leaks heap memory CVSS 4.0HIGH 8.8
  • TI-2026-76602 Double free in Pillow ImagingScaleAffine on allocation failure CVSS 4.0HIGH 8.7
  • TI-2026-76600 GIF seek in Pillow keeps rejected size, allowing denial of service CVSS 4.0HIGH 8.7
See all 110 →

Sources

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