CVE-2026-112400 Pillow: GIF seek keeps rejected size after DecompressionBombError, allowing DoS
A crafted GIF can cause memory exhaustion in Pillow if an application catches a decompression bomb error and continues processing, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-112400?
CVE-2026-112400 is a high-severity denial of service vulnerability in Python Pillow, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Pillow is a Python imaging library. From 9.2.0 until 13.0.0, Pillow can retain a rejected GIF frame size after a decompression-bomb exception. In GifImageFile._seek, a crafted GIF can leave rejected dimensions stored after Image.DecompressionBombError; if an application catches that exception and continues processing the same image object, later seek or load operations allocate according to those dimensions and can exhaust memory, denying service. This issue is fixed in version 13.0.0.
Which versions are affected by CVE-2026-112400?
3 open source packages ship an affected version, including pillow and Pillow. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
pillow Bitnami | From 9.2.0 | 13.0.0 |
pillow PyPI | From 9.2.0 | 13.0.0 |
Pillow PyPI | From 9.2.0 | 13.0.0 |
Products include Python Pillow.
How do I fix CVE-2026-112400?
Upgrade pillow to 13.0.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-112400 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-112400 exists.
Other vulnerabilities in Python Pillow
Sources
Also known as BIT-pillow-2026-112400, DEBIAN-CVE-2026-112400, ECHO-00ee-4059-247f, GHSA-65qm-jvmh-6pqg, ROOT-APP-PYPI-CVE-2026-112400, UBUNTU-CVE-2026-112400.