CVE-2026-114501

Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT > 1

State
Published
Severity
6.3 Medium
Published
Oct 21, 2026
Updated
Oct 30, 2026
Reserved
Oct 21, 2026

Read the record on cve.org

Description

Pillow is a Python imaging library. From 11.2.1 until 13.0.0, Arrow export assumes that an image's rows are tightly contiguous and exports from im->blocks[0].ptr even when PILLOW_ALIGNMENT makes aligned_linesize include row padding or an aligned offset before the first row. The resulting Arrow buffer can include uninitialized padding, bytes preceding the first row, or stale heap contents from previously freed images. Applications that configure alignment and export images to Arrow can therefore disclose one user's pixels or other process memory to another user. This issue is fixed in version 13.0.0.

Scores

CVSSScoreVectorSource
4.06.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-226 Sensitive Information in Resource Not Removed Before Reuse
  • CWE-908 Use of Uninitialized Resource

Affected Products

ProductVersions
Pillowpython-pillow
  • >= 11.2.1, < 13.0.0Affected

References

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