CVE-2026-96641
Pillow: Reachable undefined behavior in native integer operations, potentially leading to denial of service or logic integrity compromise
Description
Pillow is a Python imaging library. Prior to 13.0.0, PILfont text-width accumulation in src/_imaging.c checks positive glyph advances against INT_MAX but does not check negative advances against INT_MIN. Repeating a signed 16-bit advance of -32768 can therefore execute a signed C integer overflow in xsize += dx, producing a large positive width from a negative mathematical result. Applications that use getlength(), getsize(), or derived layout, quota, serialization, or allocation calculations can experience logic-integrity errors or resource consumption, while the high-level mask path commonly retains a decompression-bomb check. This issue is fixed in version 13.0.0.
INFO
Published Date :
Oct. 21, 2026, 9:20 p.m.
Last Modified :
Oct. 28, 2026, 2:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Pillow to version 13.0.0 or later.
- Review applications using Pillow for potential logic errors.
- Implement safe width calculations in image processing.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-96641.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-96641 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-96641
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-96641 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-96641 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 28, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-96641', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-28T01:50:02.182605Z'} -
Initial Analysis by [email protected]
Oct. 27, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* versions up to (excluding) 13.0.0 Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/commit/80de4be9e38d3a6148dd4d8491eb80cd12b760a4 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/pull/10010 Types: Issue Tracking Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/releases/tag/13.0.0 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/security/advisories/GHSA-4rm8-3hmm-39fg Types: Vendor Advisory -
New CVE Received by [email protected]
Oct. 21, 2026
Action Type Old Value New Value Added Description Pillow is a Python imaging library. Prior to 13.0.0, PILfont text-width accumulation in src/_imaging.c checks positive glyph advances against INT_MAX but does not check negative advances against INT_MIN. Repeating a signed 16-bit advance of -32768 can therefore execute a signed C integer overflow in xsize += dx, producing a large positive width from a negative mathematical result. Applications that use getlength(), getsize(), or derived layout, quota, serialization, or allocation calculations can experience logic-integrity errors or resource consumption, while the high-level mask path commonly retains a decompression-bomb check. This issue is fixed in version 13.0.0. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CWE CWE-190 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/96xxx/CVE-2026-96641.json">CVE-2026-96641</a> Added Reference https://github.com/python-pillow/Pillow/commit/80de4be9e38d3a6148dd4d8491eb80cd12b760a4 Added Reference https://github.com/python-pillow/Pillow/pull/10010 Added Reference https://github.com/python-pillow/Pillow/releases/tag/13.0.0 Added Reference https://github.com/python-pillow/Pillow/security/advisories/GHSA-4rm8-3hmm-39fg