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TI-2026-76596 Aliases CVE-2026-112396GHSA-4rr5-89j8-mwwm

Heap use-after-free in Pillow TIFF encoding to in-memory buffer

Priority LOW 34CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 1 fixed, 11 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

Pillow from 11.3.0 before 13.0.0 is affected. A heap use-after-free (CWE-416) occurs when libtiff rejects a tag while encoding TIFF data to an in-memory buffer, because the error path frees the buffer before the TIFF handle is closed. An attacker who influences TIFF tags that an application saves to BytesIO can crash the process and may enable code execution. A public exploit is linked in the references.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

Pillow is a Python imaging library. From 11.3.0 until 13.0.0, Pillow has a heap use-after-free when libtiff rejects a tag while encoding TIFF data to an in-memory buffer. When an application saves attacker-influenced TIFF tags to BytesIO, libtiff can reject a tag during encoding in ImagingLibTiffEncode; the error path then frees the output buffer without closing or clearing the TIFF handle, and later cleanup flushes through the write callback into freed memory, which can crash the process and may enable code execution. This issue is fixed in version 13.0.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00694 53rd 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: 6 advisoriesRed Hat: 1 fixed, 11 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
python-pillowPillow11.3.0 to before 13.0.013.0.0Patch availableCNA
—pillow (PyPI)11.3.0 to before 13.0.013.0.0Patch availableGHSA-4rr5-89j8-mwwm
  • Pillow Vendorpython-pillow Affected 11.3.0 to before 13.0.0 Fixed in 13.0.0 Patch available CNA
  • pillow (PyPI) Vendor— Affected 11.3.0 to before 13.0.0 Fixed in 13.0.0 Patch available GHSA-4rr5-89j8-mwwm

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*11.3.0 to before 13.0.0Vulnerablepython-pillow
  • cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* Versions 11.3.0 to before 13.0.0 Vulnerable ·python-pillow

Remediation

Upgrade Pillow to version 13.0.0 or later. Red Hat fixes Red Hat AI Inference Server 3.5 in RHSA-2026:94738, RHSA-2026:94721, RHSA-2026:94717, RHSA-2026:94715, RHSA-2026:94709 and RHSA-2026:94702. Red Hat lists no planned fix for Exploit Intelligence and lists the plan as none available for other affected products, including Red Hat Enterprise Linux 8 and Red Hat OpenShift AI (RHOAI).

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

  • Fix · CNA Pillow (python-pillow) Fixed in 13.0.0
  • Fix · GHSA-4rr5-89j8-mwwm pillow (PyPI) Fixed in 13.0.0 Advisory →

Red Hat 6 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
Show 3 more Red Hat advisories
  • 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

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Exploit IntelligenceAffectedNo fix planned: Out of support scope
Lightspeed CoreAffectedNo fix yet: Fix deferred
OpenShift LightspeedAffectedNo fix yet: Fix deferred
Red Hat AI Inference ServerAffectedNo fix yet: Fix deferred
Red Hat Ansible Automation Platform 2AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix yet: Fix deferred
Red Hat Lightspeed Services for OCPAffectedNo fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred
Red Hat Quay 3AffectedNo fix yet: Fix deferred
Red Hat Satellite 6AffectedNo fix yet: Fix deferred
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

Timeline

  1. 2026-10-20 Threatist record created from CVE-2026-112396
  2. 2026-10-20 Affected versions changed · Red Hat
  3. 2026-10-20 CVSS score added · Red Hat
  4. 2026-10-20 CISA SSVC decision points changed
  5. 2026-10-20 Priority changed: MEDIUM → LOW
  6. 2026-10-21 Alias added: GHSA-4rr5-89j8-mwwm
  7. 2026-10-21 Fix available: PyPI/[email protected] · GHSA-4rr5-89j8-mwwm
  8. 2026-10-21 CVSS score added · GHSA-4rr5-89j8-mwwm
  9. 2026-10-21 Weakness changed · GHSA-4rr5-89j8-mwwm
  10. 2026-10-21 5 new references · GHSA-4rr5-89j8-mwwm
  11. 2026-10-26 CVSS score added · NVD
  12. 2026-10-27 EPSS moved to the 50th–90th percentile
  13. 2026-11-04 Fix available: RHSA-2026:94717 · Red Hat
  14. 2026-11-04 Fix available: RHSA-2026:94715 · Red Hat
  15. 2026-11-04 Fix available: RHSA-2026:94709 · Red Hat
  16. 2026-11-04 Fix available: RHSA-2026:94738 · Red Hat
  17. 2026-11-04 Fix available: RHSA-2026:94702 · Red Hat
  18. 2026-11-04 Fix available: RHSA-2026:94721 · Red Hat
  19. 2026-11-04 Fix available: Red Hat AI Inference Server 3.5 · 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