Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-112398Pillow: Heap buffer overflow in FlashPix (FPX) JPEG decoding leads to code execution
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 0.7% (higher than 53% 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 FlashPix JPEG-tile decoder can write decoded scanlines beyond the allocated tile buffer. FlashPix (FPX) JPEG decoding selects raw mode LA with two bytes per pixel, while an unrecognized JPEG mode can be decoded as JCS_UNKNOWN with four components, causing ImagingJpegDecode to write four-component scanlines into the two-byte tile buffer. An attacker can supply a crafted OLE2 FlashPix file to an application with the optional olefile dependency installed that opens or thumbnails untrusted input. This can corrupt heap memory and may allow arbitrary code execution. This issue is fixed in version 13.0.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | python3-pillow | 5.1.1-36.el8_10 | ALSA-2026:93077 |
| AlmaLinux:8 | python3-pillow-devel | 5.1.1-36.el8_10 | ALSA-2026:93077 |
| AlmaLinux:8 | python3-pillow-doc | 5.1.1-36.el8_10 | ALSA-2026:93077 |
| AlmaLinux:8 | python3-pillow-tk | 5.1.1-36.el8_10 | ALSA-2026:93077 |
| Debian:12 | pillow | no fix listed | DEBIAN-CVE-2026-112398 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-112398 |
| Debian:14 | pillow | no fix listed | DEBIAN-CVE-2026-112398 |
| PyPI | pillow | 13.0.0 | GHSA-5x8w-8jj5-q52h |
| PyPI | pillow | 13.0.0 | PYSEC-2026-4330 |
| Rocky Linux:8 | python-pillow | 0:5.1.1-36.el8_10 | RLSA-2026:93077 |
| Ubuntu:22.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112398 |
| Ubuntu:24.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112398 |
| Ubuntu:26.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112398 |
| Ubuntu:26.10 | pillow | no fix listed | UBUNTU-CVE-2026-112398 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | < 13.0.0 |
Weakness: CWE-122, CWE-787 · 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