Answer in brief
CVE-2026-18495 records a Medium severity (CVSS 6.1) vulnerability in Libtiff: libtiff: heap-buffer overflow via numeric truncation in the jpeg raw passthrough. The current sources do not mark it as known exploited. The current feed maps Red Hat/compat-libtiff3 (generic), Red Hat/libtiff (generic), Red Hat/mingw-libtiff (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Red Hat/compat-libtiff3 (generic), Red Hat/libtiff (generic), Red Hat/mingw-libtiff (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Red Hat/compat-libtiff3generic | * | Not reported |
| Red Hat/libtiffgeneric | * | Not reported |
| Red Hat/mingw-libtiffgeneric | * | Not reported |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
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.
Quoted source text, attributed separately from HOL analysis.