Quadratic GIF comment handling in Pillow allows denial of service
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 · Low
- Fix status
- Partial Red Hat: 1 fixed, 11 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-407.
Summary
Pillow from 5.4.0 before 13.0.0 is affected. Pillow performs quadratic copying when it parses GIF comment extensions in GifImageFile._seek(), a weakness covered by CWE-407. An unauthenticated remote attacker can send a small GIF with many comment extensions to any application that opens it, consuming CPU and denying service during Image.open(). The references link an exploit.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
Pillow is a Python imaging library. From 5.4.0 until 13.0.0, Pillow performs quadratic copying while parsing GIF comments. GifImageFile._seek() repeatedly appends immutable bytes for comment sub-blocks and multiple comment extensions, and frame zero is parsed during Image.open(). An attacker can submit a small-dimension GIF containing many comment extensions to any application that opens the file. This can consume excessive CPU and deny service before the application can inspect the image. This issue is fixed in version 13.0.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| python-pillow | Pillow | 5.4.0 to before 13.0.0 | 13.0.0 | Patch available | CNA |
| — | Pillow (PyPI) | 5.4.0 to before 13.0.0 | 13.0.0 | Patch available | GHSA-74r2-7ff9-mjj2 |
- Pillow Vendorpython-pillow Affected 5.4.0 to before 13.0.0 Fixed in 13.0.0 Patch available CNA
- Pillow (PyPI) Vendor— Affected 5.4.0 to before 13.0.0 Fixed in 13.0.0 Patch available GHSA-74r2-7ff9-mjj2
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* | 5.4.0 to before 13.0.0 | Vulnerable | python-pillow |
- cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* Versions 5.4.0 to before 13.0.0 Vulnerable ·python-pillow
Remediation
Upgrade Pillow to version 13.0.0 or later. Red Hat AI Inference Server 3.5 is fixed by RHSA-2026:94738, RHSA-2026:94721, RHSA-2026:94717, RHSA-2026:94715, RHSA-2026:94709 and RHSA-2026:94702. Red Hat plans no fix for Exploit Intelligence and lists Lightspeed Core, OpenShift Lightspeed, Red Hat Enterprise Linux 8 and other products as affected without a fix.
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-74r2-7ff9-mjj2 Pillow (PyPI) Fixed in 13.0.0 Advisory →
Red Hat 6 advisories
- RHSA-2026:94738 Released 2026-11-03 · Red Hat rating CriticalRed 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 CriticalRed 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 CriticalRed 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 CriticalRed 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 CriticalRed 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 CriticalRed 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 →
| Product | Status | Plan or fix |
|---|---|---|
| Exploit Intelligence | Affected | No fix planned: Out of support scope |
| Lightspeed Core | Affected | No fix yet: Fix deferred |
| OpenShift Lightspeed | Affected | No fix yet: Fix deferred |
| Red Hat AI Inference Server | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet: Fix deferred |
| Red Hat Lightspeed Services for OCP | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
| Red Hat Quay 3 | Affected | No fix yet: Fix deferred |
| Red Hat Satellite 6 | Affected | No fix yet: Fix deferred |
| Red Hat AI Inference Server 3.5 | Fixed | RHSA-2026:94702, RHSA-2026:94709, RHSA-2026:94715, RHSA-2026:94717, RHSA-2026:94721, RHSA-2026:94738 |
Timeline
- 2026-10-20 Threatist record created from CVE-2026-112401
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-20 CISA SSVC decision points changed
- 2026-10-20 Priority changed: MEDIUM → LOW
- 2026-10-21 Alias added: GHSA-74r2-7ff9-mjj2
- 2026-10-21 Fix available: PyPI/[email protected] · GHSA-74r2-7ff9-mjj2
- 2026-10-21 CVSS score added · GHSA-74r2-7ff9-mjj2
- 2026-10-21 Weakness changed · GHSA-74r2-7ff9-mjj2
- 2026-10-21 5 new references · GHSA-74r2-7ff9-mjj2
- 2026-10-27 CVSS score added · NVD
- 2026-10-28 EPSS moved to the 50th–90th percentile
- 2026-11-04 Fix available: RHSA-2026:94717 · Red Hat
- 2026-11-04 Fix available: RHSA-2026:94715 · Red Hat
- 2026-11-04 Fix available: RHSA-2026:94709 · Red Hat
- 2026-11-04 Fix available: RHSA-2026:94738 · Red Hat
- 2026-11-04 Fix available: RHSA-2026:94702 · Red Hat
- 2026-11-04 Fix available: RHSA-2026:94721 · Red Hat
- 2026-11-04 Fix available: Red Hat AI Inference Server 3.5 · Red Hat
References
More python-pillow Pillow vulnerabilities
- 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
Sources
- CVE-2026-112401 · CVE Program
- CVE-2026-112401 · NVD
- FIRST EPSS
- GHSA-74r2-7ff9-mjj2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-112401 · Red Hat security data · CC BY 4.0
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