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No exploitation reportedFix available

CVE-2026-96644

Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)

No exploitation reported by the sources we read.

  • Published2026-10-21
  • Fixed in13.0.0
  • WeaknessCWE-125

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Pillow is a Python imaging library. Prior to 13.0.0 on Windows, src/PIL/WmfImagePlugin.py passes unchecked 32-bit WMF or EMF dimensions to the native drawwmf handler in src/display.c. The handler sizes a DIB allocation from 16-bit-truncated bcWidth and bcHeight fields but copies pixel data using the original full dimensions. A crafted wide, short metafile can pass the pixel-count decompression-bomb check and make the Windows-only renderer read beyond the heap buffer, potentially disclosing memory or crashing the process. This issue is fixed in version 13.0.0.

Timeline

dates in UTC
  1. 2026-10-2121:20CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-28 09:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-96644?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-96644?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Python pillowversion to verify
BranchAffectedFixed in
13.0< 13.0.013.0.0

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2026-96644 Red Hat Product Security85 known affected

    pillow: Pillow: Denial of Service via out-of-bounds read in metafile parser

    exploit-intelligence/vulnerability-analysis-rhel9 as a component of Exploit Intelligence · lightspeed-core/lightspeed-stack-rhel9 as a component of Lightspeed Core · lightspeed-core/rag-tool-cpu-rhel9 as a component of Lightspeed Core · +82 more

Full record on NVD

Fix

  1. Update Python pillow to 13.0.0
  2. Workaround from the vendor Red Hat Product Security CVE-2026-96644 · 85 productsMitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
  3. No fix available, says the vendor Red Hat Product Security CVE-2026-96644 · 78 productsAffected
  4. No fix planned, says the vendor Red Hat Product Security CVE-2026-96644 · 7 productsWill not fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CNACVSS 4.07.1read 2026-10-28
  • NVDCVSS 3.18.1read 2026-10-28
  • NVDweakness (CWE)CWE-125read 2026-10-28
  • FIRST EPSSEPSS score0.4 %2026-10-26
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/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
Published
2026-10-21
Last Modified
2026-10-27
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-96644?

Pillow is a Python imaging library. Prior to 13.0.0 on Windows, src/PIL/WmfImagePlugin.py passes unchecked 32-bit WMF or EMF dimensions to the native drawwmf handler in src/display.c. The handler sizes a DIB allocation from 16-bit-truncated bcWidth and bcHeight fields but copies pixel data using the original full dimensions. A crafted wide, short metafile can pass the pixel-count decompression-bomb check and make the Windows-only renderer read beyond the heap buffer, potentially disclosing memory or crashing the process. This issue is fixed in version 13.0.0.

Is CVE-2026-96644 actively exploited?

Active exploitation of CVE-2026-96644 has not been confirmed. Its EPSS score was 0.4% on 2026-10-26, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-96644?

CVE-2026-96644 has a CVSS v3 base score of 8.1 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H.

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