# CVE-2026-18495: libtiff heap buffer overflow in tiff2pdf

Source: https://junglewise.ai/threats/cve-2026-18495-libtiff-heap-buffer-overflow-in-tiff2pdf  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-11. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-18495 · Severity: medium · CVSS 6.1 · Published 2026-09-11

A flaw in libtiff's tiff2pdf utility allows attackers to trigger a heap buffer overflow by submitting specially crafted BigTIFF image files. The vulnerability leads to memory corruption and application crashes, potentially enabling code execution or denial of service. Organizations using libtiff for image conversion should apply patches promptly.

Technologies: [Libtiff](https://junglewise.ai/threats/technologies/libtiff). Vendors: [Libtiff](https://junglewise.ai/threats/vendors/libtiff).

## Quick answers

**Is CVE-2026-18495 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18495 being exploited in the wild.

**How severe is CVE-2026-18495?** Medium severity, with a CVSS score of 6.1, published 11 September 2026.

**Which products and versions are affected?** libtiff libtiff.

**Is there a fix for CVE-2026-18495?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-18495?** Check whether you run Libtiff. 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 a heap-buffer overflow caused by an integer truncation error in tiff2pdf when processing BigTIFF files. A 64-bit `StripByteCounts` value is truncated to a 32-bit integer during memory allocation, resulting in undersized heap allocation. An attacker can supply a malicious BigTIFF file to trigger an out-of-bounds memory copy, leading to heap corruption, crashes, and potential arbitrary code execution. The attack requires no authentication and is triggered by processing a crafted file; patch availability should be confirmed with the vendor.

## Affected products

- libtiff libtiff

## Timeline

- 2026-09-11: disclosed

## References

- [https://catalog.redhat.com/software/containers/](https://catalog.redhat.com/software/containers/)
- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)

## Related threats

- [libtiff integer overflow in thumbnail buffer allocation](https://junglewise.ai/threats/cve-2026-52491-libtiff-integer-overflow-in-thumbnail-buffer-allocation)
- [libtiff integer overflow in rgb2ycbcr cvtRaster](https://junglewise.ai/threats/cve-2026-52492-libtiff-integer-overflow-in-rgb2ycbcr-cvtraster)
- [libtiff integer overflow in tiffcrop -S option](https://junglewise.ai/threats/cve-2026-52490-libtiff-integer-overflow-in-tiffcrop-s-option)
- [libtiff heap overflow in PixarLogDecode with 8BITABGR format](https://junglewise.ai/threats/cve-2026-12912-libtiff-heap-overflow-in-pixarlogdecode-with-8bitabgr-format)
- [Libtiff write-what-where condition in TIFF image processing](https://junglewise.ai/threats/cve-2025-9900-libtiff-write-what-where-condition-in-tiff-image-processing)