Pillow: Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO

Pillow (pip)

``` ============================================================================ Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO Location: src/libImaging/TiffDecode.c:94 in _tiffWriteProc() Commit: a707c6b21c313880d0771e54965d142dd42358b6 ============================================================================ ``` Pillow can write…

First seen: 21 Oct 2026
Last update: 21 Oct 2026, 21:28 UTC
Fixed in: Pillow 13.0.0
Identifiers: CVE-2026-112393
CVSS: 9.2
Source: GitHub advisory
On the menu as: PyPI packages
Python

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Pillow: Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO
Severity: critical. Patch status: patched.
Affected: Pillow (pip)
Fixed in: Pillow 13.0.0
Ids: CVE-2026-112393

``` ============================================================================ Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO Location: src/libImaging/TiffDecode.c:94 in _tiffWriteProc() Commit: a707c6b21c313880d0771e54965d142dd42358b6 ============================================================================ ``` Pillow can write…

## Steps
1. Search every lockfile and manifest (package-lock.json, yarn.lock, pnpm-lock.yaml, requirements*.txt, poetry.lock, uv.lock, composer.lock, go.sum, Cargo.lock, Gemfile.lock) for `Pillow`. For each hit, compare the installed version with the fix on the same major line: Pillow 13.0.0. If it's lower, give the exact upgrade command for the package manager this repo uses.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-112393") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://github.com/advisories/GHSA-332p-7hrc-92wf https://github.com/python-pillow/Pillow/commit/11582e5ffbdceb973d5ee593f3105af5a9852b40 https://github.com/python-pillow/Pillow/releases/tag/13.0.0 https://github.com/python-pillow/Pillow/security/advisories/GHSA-332p-7hrc-92wf https://nvd.nist.gov/vuln/detail/CVE-2026-112393
https://pwned.coffee/i/pillow-heap-buffer-overflow-in-tiffwriteproc-when-saving-cve-2026-112393

Sources

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