CVE-2026-112898Pillow: Image.quantize() with empty palette leaks uninitialized stack memory

Descripción

Pillow is a Python imaging library. From 9.1.0 until 13.0.0, Pillow can disclose uninitialized stack memory when Image.quantize() uses an empty palette. ImagingPaletteCacheUpdate() leaves a local cache array uninitialized when the palette has zero entries, and the conversion path emits those bytes as output pixel indices. An attacker who controls the palette image can obtain stack contents from a returned PNG or GIF. This can disclose addresses and stack-canary data without an out-of-bounds access, memory corruption, or process crash. This issue is fixed in version 13.0.0.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

Correcciones de Ubuntu

• USN-9064-1 Pillow vulnerabilities Ubuntu 26.10, 26.04, 24.04, 22.04, 20.04, 18.04, 16.04, 14.04 · 12.11.2026 · pillow

Referencias y parches

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-rfgq-q3w2-pmv2 ExploitMitigationVendor Advisory
• https://github.com/python-pillow/Pillow/commit/13943c8f857b22f073d30f0ef9b725a0d255f1a4 Patch
• https://github.com/python-pillow/Pillow/releases/tag/13.0.0 Release Notes