Heap-based Buffer Overflow Affecting pillow package, versions [,13.0.0)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-PILLOW-21277801
- published20 Oct 2026
- disclosed19 Oct 2026
- creditNicholas Carlini, Tomer Fichman
Introduced: 19 Oct 2026
NewCVE-2026-112393 (opens in a new tab)How to fix?
Upgrade pillow to version 13.0.0 or higher.
Overview
Affected versions of this package are vulnerable to Heap-based Buffer Overflow via _tiffWriteProc in src/libImaging/TiffDecode.c when saving a TIFF image to a BytesIO object. The buffer size calculation uses state->size instead of the current write location (state->loc) when determining whether reallocation is needed, so when libtiff seeks past the end of the allocated buffer (for example, when writing the TIFF directory), the computed to_write value becomes negative and the subsequent _TIFFmemcpy writes beyond the allocated heap region. An attacker who can supply an image that is saved as a TIFF to an in-memory buffer can trigger the overflow, achieving arbitrary heap corruption with potential for remote code execution.
Note: Exploitation requires that an attacker-controlled out-of-line tag value (such as ImageDescription, DocumentName, XMP, or an embedded ICC profile) reaches libtiff during the save operation, and that the application saves the result into a non-file object such as BytesIO.