Medium severity · published May 9, 2026
CVE-2026-42309
Pillow: Heap buffer overflow with nested list coordinates
5.5
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PI
Pillow · python-pillow
>= 11.2.1, < 12.2.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42309
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42309
Product
https://github.com/python-pillow/Pillow/releases/tag/12.2.0
Vendor Advisory
https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xmw-vc9v-4wf2
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