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TI-2026-78991 Aliases CVE-2026-96638GHSA-24rc-8hj2-v98c

Memory exhaustion in Pillow BMP RLE decoder enables denial of service

Priority LOW 29CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
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 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.

Summary

Pillow from 9.1.0 before 13.0.0 is affected. The BMP RLE decoder in BmpRleDecoder.decode() does not limit how much data crafted delta escapes and absolute-mode runs append (CWE-770). A remote attacker can supply a kilobyte-sized crafted BMP file with a large width, which expands to hundreds of megabytes of memory when a user opens it. This exhausts memory and causes denial of service.

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

Description from the CNA

Pillow is a Python imaging library. From 9.1.0 until 13.0.0, BmpRleDecoder.decode() in src/PIL/BmpImagePlugin.py permits crafted RLE BMP delta escapes and absolute-mode runs to append beyond the remaining dest_length without a per-branch cap. A delta can add roughly 255 image rows in one iteration, so a kilobyte-sized file with a large but permitted width can expand the data bytearray to hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00345 28th percentileScored 2026-11-07
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-pillowPillow9.1.0 to before 13.0.013.0.0Patch availableCNA
—pillow (PyPI)9.1.0 to before 13.0.013.0.0Patch availableGHSA-24rc-8hj2-v98c
  • Pillow Vendorpython-pillow Affected 9.1.0 to before 13.0.0 Fixed in 13.0.0 Patch available CNA
  • pillow (PyPI) Vendor— Affected 9.1.0 to before 13.0.0 Fixed in 13.0.0 Patch available GHSA-24rc-8hj2-v98c

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*9.1.0 to before 13.0.0Vulnerablepython-pillow
  • cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* Versions 9.1.0 to before 13.0.0 Vulnerable ·python-pillow

Remediation

Upgrade Pillow to version 13.0.0 or later, which fixes both the Pillow and PyPI pillow packages. 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. The sources list no fixed version for Exploit Intelligence, Lightspeed Core, OpenShift Lightspeed, Red Hat Ansible Automation Platform 2 and other products.

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-24rc-8hj2-v98c 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. 2026-10-21 Threatist record created from CVE-2026-96638
  2. 2026-10-22 Alias added: GHSA-24rc-8hj2-v98c
  3. 2026-10-22 Fix available: PyPI/[email protected] · GHSA-24rc-8hj2-v98c
  4. 2026-10-22 CVSS score added · GHSA-24rc-8hj2-v98c
  5. 2026-10-22 Weakness changed · GHSA-24rc-8hj2-v98c
  6. 2026-10-22 6 new references · GHSA-24rc-8hj2-v98c
  7. 2026-10-23 Affected versions changed · Red Hat
  8. 2026-10-23 CVSS score added · Red Hat
  9. 2026-10-23 Priority changed: MEDIUM → LOW
  10. 2026-10-28 CISA SSVC decision points changed
  11. 2026-11-04 Fix available: RHSA-2026:94717 · Red Hat
  12. 2026-11-04 Fix available: RHSA-2026:94715 · Red Hat
  13. 2026-11-04 Fix available: RHSA-2026:94709 · Red Hat
  14. 2026-11-04 Fix available: RHSA-2026:94738 · Red Hat
  15. 2026-11-04 Fix available: RHSA-2026:94702 · Red Hat
  16. 2026-11-04 Fix available: RHSA-2026:94721 · Red Hat
  17. 2026-11-04 Fix available: Red Hat AI Inference Server 3.5 · Red Hat

References

Patch 1

Advisory 2

Other 3

  • 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