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Fencer Intel
medium 5.3

CVE-2026-59203 json

Pillow EpsImagePlugin negative %%BeginBinary byte count causes infinite loop denial of service

published 4mo ago modified 18d ago also BIT-pillow-2026-59203 , EUVD-2026-43741 , GHSA-pg7v-jwj7-p798 , PYSEC-2026-3452

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

Pillow is a Python imaging library. From 12.0.0 through 12.2.0, Pillow's EPS parser in PIL/EpsImagePlugin.py accepts a negative byte count in the %%BeginBinary directive, allowing a crafted EPS file to cause Image.open() to seek backwards to the same directive and parse it repeatedly in an infinite loop. This issue is fixed in version 12.3.0.

Patch / fix

  • pypi pillow 12.3.0
  • bitnami pillow 12.3.0
  • python pillow 12.3.0
  • pillow Debian 14 12.3.0-1

debian advisories DEBIAN-CVE-2026-59203

  • pillow Ubuntu 26.04 LTS 12.1.1-2ubuntu1.4

ubuntu advisories UBUNTU-CVE-2026-59203

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2026-59203 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-59203 updated cvss 5.3

Pillow: Pillow: Denial of Service via crafted EPS file

  • Red Hat Lightspeed Core lightspeed-core/rag-tool-cpu-rhel9, lightspeed-core/lightspeed-stack-rhel9, lightspeed-core/rag-tool-cuda-12.9-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed/lightspeed-service-api-rhel9, openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9 Red Hat AI Inference Server rhaii/vllm-cpu-rhel9, rhaii/vllm-tpu-rhel9, rhaii/vllm-cuda-rhel9, rhaii/vllm-rocm-rhel9, rhaiis/vllm-cpu-rhel9, rhaiis/vllm-tpu-rhel9, +9 more Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-gaudi-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9, +1 more Red Hat OpenShift AI (RHOAI) rhoai/odh-automl-rhel9, rhoai/odh-mlflow-rhel9, rhoai/odh-autorag-rhel9, rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-llm-d-kv-cache-rhel9, rhoai/odh-llama-stack-core-rhel9, +27 more Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Exploit Intelligence exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 Red Hat Ansible Automation Platform 2 python-pillow 10.3.0-1.el9ap, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, ansible-automation-platform/automation-dashboard-rhel9, ansible-automation-platform-25/lightspeed-chatbot-rhel8, ansible-automation-platform-26/lightspeed-chatbot-rhel9, +1 more Red Hat Enterprise Linux 7 python-pillow, python-pillow-qt, python-pillow-tk, python-pillow-sane, python-pillow 10.3.0-1.el9ap Red Hat Enterprise Linux 8 python3-pillow, python3-pillow-tk, python-pillow 10.3.0-1.el9ap Red Hat Satellite 6 python-pillow 10.3.0-1.el9ap, python-pillow 12.2.0-1.el8pc
    under investigation
  • Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/disk-image-cuda-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-caikit-nlp-rhel9, rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-kserve-controller-rhel9, rhoai/odh-llm-d-inference-scheduler-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/python-pillow/Pillow/security/advisories/GHSA-pg7v-jwj7-p798 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi pillow
>=12.0.0, <12.3.0
12.3.0
bitnami pillow
>=12.0.0, <12.3.0
12.3.0

Affected products

  • python-pillow Pillow

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of python-pillow/Pillow published their own advisory on GitHub. Reviewed sources take precedence over it.