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Fencer Vulns
medium 5.5

CVE-2026-42309 json

Pillow: Heap buffer overflow with nested list coordinates

published 2026-05-04 6 mo ago modified 2026-10-19 20 d ago also BIT-pillow-2026-42309 , EUVD-2026-28901 , GHSA-5xmw-vc9v-4wf2 , PYSEC-2026-2251

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

Pillow is a Python imaging library. From version 11.2.1 to before version 12.2.0, passing nested lists as coordinates to APIs that accept coordinates such as ImagePath.Path, ImageDraw.ImageDraw.polygon and ImageDraw.ImageDraw.line could cause a heap buffer overflow, as nested lists were recursively unpacked beyond the allocated buffer. Coordinate lists are now validated to contain exactly two numeric coordinates. This issue has been patched in version 12.2.0.

Patch / fix

  • pypi pillow 12.2.0
  • bitnami pillow 12.2.0
  • python pillow 12.2.0
  • pillow Debian 14 12.2.0-1

debian advisories DEBIAN-CVE-2026-42309

  • pillow Ubuntu 25.10 11.3.0-1ubuntu1.3
  • pillow Ubuntu 26.04 LTS 12.1.1-2ubuntu1.2

ubuntu advisories UBUNTU-CVE-2026-42309

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

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-2026-42309 updated cvss 5.1

Pillow: Pillow: Denial of Service via specially crafted coordinate input

  • Red Hat Exploit Intelligence exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed/lightspeed-service-api-rhel9 Red Hat Pen Drive Powered by Red Hat Lightspeed pen-drive/pen-drive-scanner-rhel9 Red Hat AI Inference Server rhaiis/vllm-cpu-rhel9, rhaiis/vllm-tpu-rhel9, rhaiis/vllm-spyre-rhel9, rhaiis/vllm-neuron-rhel9 Red Hat Ansible Automation Platform 2 python-pillow, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform/automation-dashboard-rhel9, ansible-automation-platform-25/lightspeed-chatbot-rhel8, ansible-automation-platform-26/lightspeed-chatbot-rhel9 Red Hat Enterprise Linux 7 python-pillow, python-pillow-qt, python-pillow-tk, python-pillow-sane
    +5 more products
    Red Hat Enterprise Linux 8 python-pillow, python3-pillow, python3-pillow-tk Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/disk-image-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9, +1 more Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9, rhoai/odh-vllm-cuda-rhel9, rhoai/odh-vllm-rocm-rhel9, rhoai/odh-caikit-nlp-rhel9, rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-kserve-agent-rhel9, +25 more Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9 Red Hat Satellite 6 python-pillow
    affected: no fix available “Fix deferred”
  • Red Hat AI Inference Server 3.3 rhaiis 1778244531, rhaiis 1778244559, rhaiis 1778274666
    fixed: vendor fix RHSA-2026:16008
  • Red Hat AI Inference Server 3.4 rhaii/vllm-spyre-rhel9 1787151840
    fixed: vendor fix RHSA-2026:57387

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
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
GitHub 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 5.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi pillow
>=11.2.1, <12.2.0
12.2.0
bitnami pillow
>=11.2.1, <12.2.0
12.2.0

Affected products

  • python-pillow Pillow

Classification

Weakness
  • CWE-122 Heap-based Buffer Overflow

References

Sources

Fencer Vulns 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.