Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-112403Pillow: Heap buffer overflow in ImagingJpegDecode
Critical 9.2
In plain English
A critical-severity heap buffer overflow in Pillow from python-pillow. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's JPEG decoder can write a full-width scanline into a buffer sized for a requested draft scale. ImagingJpegDecode does not verify libjpeg's actual output width and component count after scaling is requested, and an 8-bit lossless SOF3 JPEG decoded by a build linked to libjpeg-turbo 3.x can ignore the requested downscaling geometry. An attacker can supply such a JPEG to an application that uses draft() or thumbnail() to request downscaling. This can corrupt heap memory, crash the process, or potentially allow code execution. Older libjpeg-turbo 2.x and IJG builds reject the SOF3 input. This issue is fixed in version 13.0.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | pillow | no fix listed | DEBIAN-CVE-2026-112403 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-112403 |
| Debian:14 | pillow | no fix listed | DEBIAN-CVE-2026-112403 |
| PyPI | pillow | 13.0.0 | GHSA-8g5g-8vmr-9782 |
| PyPI | pillow | 13.0.0 | PYSEC-2026-4332 |
| Ubuntu:22.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112403 |
| Ubuntu:24.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112403 |
| Ubuntu:26.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112403 |
| Ubuntu:26.10 | pillow | no fix listed | UBUNTU-CVE-2026-112403 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | < 13.0.0 |
Weakness: CWE-122 · Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N