CVE-2026-112401: CWE-407: Inefficient Algorithmic Complexity in python-pillow Pillow
Description
CVE-2026-112401 is a vulnerability in the python-pillow Pillow library affecting versions from 5.4.0 up to but not including 13.0.0. The issue involves inefficient quadratic copying when parsing GIF comments, specifically in the GifImageFile._seek() method. This inefficiency can be exploited by an attacker submitting a crafted GIF with many comment extensions, causing excessive CPU consumption and potential denial of service before the image is fully inspected. The vulnerability is fixed in version 13.0.0.
CVSS v4.0
Score 6.9medium
Affected software
python-pillow
Pillow
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Pillow Python imaging library versions >=5.4.0 and <13.0.0 contain an inefficient algorithmic complexity issue (CWE-407) in the GifImageFile._seek() function. When parsing GIF comment sub-blocks and multiple comment extensions, the method repeatedly appends immutable bytes, resulting in quadratic copying behavior. An attacker can exploit this by providing a small-dimension GIF with numerous comment extensions, leading to excessive CPU usage and denial of service during image opening. The flaw is resolved in Pillow version 13.0.0.
Potential Impact
An attacker can cause excessive CPU consumption and denial of service in applications that open crafted GIF images containing many comment extensions. This can degrade application availability and performance before the image is fully processed. There is no indication of code execution or data corruption from the provided data.
Mitigation Recommendations
Upgrade Pillow to version 13.0.0 or later where this issue is fixed. No other mitigations are indicated or necessary according to the available information.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-19T16:58:51.959Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad68cd42cdf04f65692eec1
Added to database: 10/19/2026, 21:34:12 UTC
Last enriched: 10/19/2026, 21:48:32 UTC
Last updated: 10/19/2026, 21:48:32 UTC
Views: 4
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.