Heap buffer overflow in Pillow JPEG encoder when writing comments
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · 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-787 and the CVSS impact.
Summary
Pillow from 9.4.0 before 13.0.0 contains a heap buffer overflow (CWE-787) in its JPEG encoder. When an ICC profile exactly fills the encoder buffer, writing a JPEG comment goes one byte past the buffer, which lets attacker-controlled data overwrite adjacent heap memory. An attacker can supply an untrusted image that, when re-saved as JPEG with its ICC profile and comment kept, crashes the process and may enable code execution in suitable runtime and heap layouts.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
Pillow is a Python imaging library. From 9.4.0 until 13.0.0, ImagingJpegEncode() in src/libImaging/JpegEncode.c can call jpeg_write_marker() for a JPEG COM comment when an ICC profile has exactly filled the 65536-byte encoder buffer. libjpeg writes one byte before checking the exhausted free_in_buffer counter, which then wraps and permits the attacker-controlled comment and subsequent compressed image data to overwrite adjacent heap memory. Re-saving an untrusted image as JPEG while preserving its ICC profile and forwarded comment can crash the process and may enable code execution in suitable runtime and heap layouts. 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
- No
- Technical impact
- Total
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 | 9.4.0 to before 13.0.0 | 13.0.0 | Patch available | CNA |
| — | Pillow (PyPI) | 9.4.0 to before 13.0.0 | 13.0.0 | Patch available | GHSA-g7cr-3p24-7wf7 |
- Pillow Vendorpython-pillow Affected 9.4.0 to before 13.0.0 Fixed in 13.0.0 Patch available CNA
- Pillow (PyPI) Vendor— Affected 9.4.0 to before 13.0.0 Fixed in 13.0.0 Patch available GHSA-g7cr-3p24-7wf7
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* | 9.4.0 to before 13.0.0 | Vulnerable | python-pillow |
- cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* Versions 9.4.0 to before 13.0.0 Vulnerable ·python-pillow
Remediation
Upgrade Pillow to version 13.0.0 or later. Red Hat fixes are RHSA-2026:92510 for Red Hat OpenShift AI 3.4, RHSA-2026:94631 for Red Hat OpenShift AI 3.5, RHSA-2026:94702, RHSA-2026:94709, RHSA-2026:94715, RHSA-2026:94717, RHSA-2026:94721 and RHSA-2026:94738 for Red Hat AI Inference Server 3.5, RHSA-2026:95655 for Red Hat Satellite 6.16, RHSA-2026:95656 for Red Hat Satellite 6.17, RHSA-2026:95657 for Red Hat Satellite 6.18 and RHSA-2026:92861 for Red Hat Satellite 6.19. The sources list no fixed version for Red Hat AI Inference Server.
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-g7cr-3p24-7wf7 Pillow (PyPI) Fixed in 13.0.0 Advisory →
Red Hat 12 advisories
- RHSA-2026:95655 Released 2026-11-05 · Red Hat rating CriticalSatellite 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 CriticalSatellite 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 CriticalSatellite 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 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
- 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
- RHSA-2026:94631 Released 2026-11-03 · Red Hat rating CriticalGuideLLM 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 CriticalSatellite 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 CriticalRHOAI 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 →
| Product | Status | Plan or fix |
|---|---|---|
| Exploit Intelligence | Affected | No fix yet |
| Lightspeed Core | Affected | No fix yet |
| OpenShift Lightspeed | Affected | No fix yet |
| Red Hat AI Inference Server | Affected | No fix planned: Will not fix |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | No fix yet |
| Red Hat Lightspeed Services for OCP | Affected | No fix yet |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet |
| Red Hat Quay 3 | Affected | No fix yet |
| 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 |
| Red Hat OpenShift AI 3.4 | Fixed | RHSA-2026:92510 |
| Red Hat OpenShift AI 3.5 | Fixed | RHSA-2026:94631 |
| Red Hat Satellite 6.16 for RHEL 8 | Fixed | RHSA-2026:95655 |
| Red Hat Satellite 6.16 for RHEL 9 | Fixed | RHSA-2026:95655 |
| Red Hat Satellite 6.17 for RHEL 9 | Fixed | RHSA-2026:95656 |
| Red Hat Satellite 6.18 for RHEL 9 | Fixed | RHSA-2026:95657 |
| Red Hat Satellite 6.19 for RHEL 9 | Fixed | RHSA-2026:92861 |
Not affected: 9 products
- 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
- 2026-10-21 Threatist record created from CVE-2026-96778
- 2026-10-22 Alias added: GHSA-g7cr-3p24-7wf7
- 2026-10-22 Fix available: PyPI/[email protected] · GHSA-g7cr-3p24-7wf7
- 2026-10-22 CVSS score added · GHSA-g7cr-3p24-7wf7
- 2026-10-22 Weakness changed · GHSA-g7cr-3p24-7wf7
- 2026-10-22 6 new references · GHSA-g7cr-3p24-7wf7
- 2026-10-23 Affected versions changed · Red Hat
- 2026-10-23 CVSS score added · Red Hat
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-10-24 Affected versions changed · Red Hat
- 2026-10-27 CVSS score added · NVD
- 2026-10-28 CISA SSVC decision points changed
- 2026-10-30 Fix available: RHSA-2026:92510 · Red Hat
- 2026-10-30 Fix available: Red Hat OpenShift AI 3.4 · Red Hat
- 2026-10-30 Fix available: Red Hat Satellite 6.19 for RHEL 9 · Red Hat
- 2026-10-31 Fix available: RHSA-2026:92861 · Red Hat
- 2026-11-04 Affected versions changed · Red Hat
- 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-2026:94631 · 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 OpenShift AI 3.5 · Red Hat
- 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
- 2026-11-06 Fix available: RHSA-2026:95656 · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95655 · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95657 · Red Hat
References
Advisory 2
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-2026-96778 · CVE Program
- CVE-2026-96778 · NVD
- FIRST EPSS
- GHSA-g7cr-3p24-7wf7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-96778 · Red Hat security data · CC BY 4.0
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