CVE-2026-18495
Description
A flaw was found in libtiff. A heap-buffer overflow vulnerability exists in the tiff2pdf utility due to an integer truncation error when processing crafted BigTIFF files. An attacker can provide a specially crafted BigTIFF file, causing a 64-bit StripByteCounts value to be truncated to a 32-bit integer. This leads to an undersized memory allocation and a subsequent out-of-bounds memory copy, resulting in a crash and severe memory corruption.
Statement
This vulnerability is classified as having a Moderate impact because exploitation is restricted to the standalone tiff2pdf conversion utility and requires an attacker to convince a user or automated pipeline to process a specially crafted BigTIFF image. Core shared libraries in libtiff and standard Red Hat Enterprise Linux system services do not expose this functionality over the network by default. While memory corruption or denial of service through an application crash can occur, the blast radius is strictly limited to the privileges of the local process executing the tool.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.1 | N/A | 6.1 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H
Acknowledgements
Red Hat would like to thank Jinbao Chen for reporting this issue.
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