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CVE-2026-112898GHSA-RFGQ-Q3W2-PMV2BIT-PILLOW-2026-112898

Pillow: Image.quantize() with empty palette leaks uninitialized stack memory

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 13.0.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. First seen by cve.now
  3. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: partial

  4. Record last updated

Affected versions

  • python-pillow Pillow

    From 9.1.0 · fixed in 13.0.0

  • pillowPyPI

    From 9.1.0 · fixed in 13.0.0

  • pillowBitnami

    From 9.1.0 · fixed in 13.0.0

References 3

GitHub · python-pillow/Pillow