# CVE-2026-114501: Pillow Arrow export memory disclosure via row padding

Source: https://junglewise.ai/threats/cve-2026-114501-pillow-is-a-python-imaging-library-from-11-2-1-until-13-0-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-114501 · Severity: medium · CVSS 4 · Published 2026-10-21

Pillow is a Python library for image processing. When configured with memory alignment and exporting images to Apache Arrow format, it fails to account for row padding, potentially exposing uninitialized memory, stale heap contents from previous images, or another user's image data to any process reading the exported data.

Technologies: [pillow (PyPI)](https://junglewise.ai/threats/technologies/pillow), [Python Pillow Pillow](https://junglewise.ai/threats/technologies/python-pillow-pillow). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi), [Python Pillow](https://junglewise.ai/threats/vendors/python-pillow).

## Quick answers

**Is CVE-2026-114501 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-114501 being exploited in the wild.

**How severe is CVE-2026-114501?** Medium severity, with a CVSS score of 4, published 21 October 2026.

**Which products and versions are affected?** pillow (PyPI) >= 11.2.1, < 13.0.0, ECOSYSTEM:introduced=11.2.1,fixed=13.0.0; Python Pillow Pillow 11.2.1 to 13.0.0.

**Is there a fix for CVE-2026-114501?** Yes. pillow (PyPI): upgrade to 13.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-114501 attacked?** It is attacked with local access or over the network, in a software library.

**Am I affected by CVE-2026-114501?** Check whether you run pillow (PyPI) or Python Pillow Pillow at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- pillow (PyPI): upgrade to 13.0.0 or later

  ```sh
  pip install "pillow>=13.0.0"
  ```


## Technical details

The Arrow export function in Pillow 11.2.1–13.0.0 incorrectly exports image data starting at im->blocks[0].ptr without adjusting for alignment-induced row padding or aligned offsets before the first row. This causes the exported Arrow buffer to contain uninitialized padding bytes or stale heap contents from previously freed images. The vulnerability affects applications that use PILLOW_ALIGNMENT and export images to Arrow; no user interaction or authentication is required beyond calling the export function.

## Affected products

- Python Pillow Pillow 11.2.1 to 13.0.0

## Identifiers

- CVE-2026-114501
- BIT-PILLOW-2026-114501
- GHSA-654x-cwwv-5j9c
- PYSEC-2026-4336

## Timeline

- 2026-10-21: disclosed
- 2026-10-12: patched: Fix committed; version 13.0.0 released

## References

- [https://github.com/python-pillow/Pillow/commit/19f64946eb247b973dd4560be7dea3bf979d2e6a](https://github.com/python-pillow/Pillow/commit/19f64946eb247b973dd4560be7dea3bf979d2e6a)
- [https://github.com/python-pillow/Pillow/pull/10172](https://github.com/python-pillow/Pillow/pull/10172)

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