# CVE-2026-54604: OpenSlide uninitialized memory disclosure in TIFF decoding

Source: https://junglewise.ai/threats/cve-2026-54604-openslide-uninitialized-memory-disclosure-in-tiff-decoding  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-54604 · Severity: info · CVSS 0 · Published 2026-09-17

OpenSlide is a C library used by medical imaging software and digital pathology applications to read whole slide image files. A behavior change in the libtiff 4.7.1 library causes OpenSlide to return uninitialized heap memory in pixel data when reading regions near the edges of TIFF-based slides. An attacker could craft a malicious slide file that, when processed by a network service, leaks sensitive data from memory or displays corrupted image data to end users.

Technologies: [OpenSlide](https://junglewise.ai/threats/technologies/openslide). Vendors: [OpenSlide](https://junglewise.ai/threats/vendors/openslide).

## Quick answers

**Is CVE-2026-54604 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-54604 being exploited in the wild.

**How severe is CVE-2026-54604?** Informational severity, with a CVSS score of 0, published 17 September 2026.

**Which products and versions are affected?** OpenSlide 4.0.0.9 through 4.0.0.11, 4.0.0 and 4.0.0.10 (binary builds).

**Is there a fix for CVE-2026-54604?** A patch was published on 2026-03-09: Fix merged for openslide-bin Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-54604 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-54604?** Check whether you run OpenSlide 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.

## Technical details

The vulnerability is an information disclosure caused by a regression in libtiff 4.7.1's tile reading behavior. When OpenSlide's TIFF decoder (_openslide_tiff_read_tile() in src/openslide-decode-tiff.c) processes a partial bottom tile row in non-JPEG/non-JP2K TIFF formats, it requests a full-height destination buffer from libtiff, which may contain uninitialized heap memory. This uninitialized data is then returned to callers of openslide_read_region(). The vulnerability affects OpenSlide versions 4.0.0.9 through 4.0.0.11, and depends on libtiff 4.7.1 being in use; libtiff 4.7.0 and earlier do not exhibit the regression. The issue is fixed in OpenSlide 4.0.1 and binary build 4.0.0.12, which work around the libtiff regression.

## Affected products

- OpenSlide OpenSlide 4.0.0.9 through 4.0.0.11, 4.0.0 and 4.0.0.10 (binary builds)

## Timeline

- 2026-03-05: disclosed: Issue reported on GitHub
- 2026-03-09: patched: Fix merged for openslide-bin
- 2026-09-17: patched: OpenSlide 4.0.1 and binary build 4.0.0.12 released with fix
- 2026-09-17: advisory: CVE-2026-54604 published

## References

- [https://github.com/openslide/openslide-bin/issues/433](https://github.com/openslide/openslide-bin/issues/433)
- [https://github.com/openslide/openslide-bin/pull/436](https://github.com/openslide/openslide-bin/pull/436)

## Related threats

- [OpenSlide heap out-of-bounds read in MIRAX reader](https://junglewise.ai/threats/cve-2026-111130-openslide-through-4-0-1-contains-a-heap-out-of-bounds-read)
- [OpenSlide buffer overflow in Ventana BIF file parsing](https://junglewise.ai/threats/cve-2026-48977-openslide-buffer-overflow-in-ventana-bif-file-parsing)