Pillow is a Python imaging library. From 11.3.0 until 13.0.0, Pillow has a heap use-after-free when libtiff rejects a tag while encoding TIFF data to an in-memory buffer. When an application saves attacker-influenced TIFF tags to BytesIO, libtiff can reject a tag during encoding in ImagingLibTiffEncode; the error path then frees the output buffer without closing or clearing the TIFF handle, and later cleanup flushes through the write callback into freed memory, which can crash the process and may enable code execution. This issue is fixed in version 13.0.0.
History

Mon, 26 Oct 2026 21:15:00 +0000

Type Values Removed Values Added
First Time appeared Python
Python pillow
CPEs cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*
Vendors & Products Python
Python pillow

Tue, 20 Oct 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 20 Oct 2026 00:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-825
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 19 Oct 2026 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Python-pillow
Python-pillow pillow
Vendors & Products Python-pillow
Python-pillow pillow

Mon, 19 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Description Pillow is a Python imaging library. From 11.3.0 until 13.0.0, Pillow has a heap use-after-free when libtiff rejects a tag while encoding TIFF data to an in-memory buffer. When an application saves attacker-influenced TIFF tags to BytesIO, libtiff can reject a tag during encoding in ImagingLibTiffEncode; the error path then frees the output buffer without closing or clearing the TIFF handle, and later cleanup flushes through the write callback into freed memory, which can crash the process and may enable code execution. This issue is fixed in version 13.0.0.
Title Pillow: Heap use-after-free when encoding TIFF to an in-memory buffer
Weaknesses CWE-416
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-19T21:02:15.197Z

Updated: 2026-10-20T16:09:21.913Z

Reserved: 2026-10-19T16:58:51.959Z

Link: CVE-2026-112396

cve-icon Vulnrichment

Updated: 2026-10-20T15:10:27.591Z

cve-icon NVD

Status : Analyzed

Published: 2026-10-19T22:17:06.837

Modified: 2026-10-26T21:00:38.780

Link: CVE-2026-112396

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-19T21:02:15Z

Links: CVE-2026-112396 - Bugzilla