Vulnerability · Published Nov 3, 2026 · Assigned by VulDB
CVE-2026-121517IrfanView TIFF Wang Annotation heap-based overflow
Medium 5.0
In plain English
A medium-severity heap buffer overflow in IrfanView. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).
Official description
A vulnerability was detected in IrfanView 4.76.0.0 on Win64. Affected by this vulnerability is an unknown functionality of the component TIFF Wang Annotation Handler. Performing a manipulation results in heap-based buffer overflow. The attack is possible to be carried out remotely. The complexity of an attack is rather high. The exploitation appears to be difficult. The exploit is now public and may be used. It is recommended to apply a patch to fix this issue. The vendor confirms: "[T]he TIF-Annotations option is OFF by default. Means, normal users are not affected ... the danger level for this is low".
Affected products (as reported)
Weakness: CWE-122, CWE-119 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
References
- VDB-430288 | IrfanView TIFF Wang Annotation heap-based overflow vdb-entry
- VDB-430288 | CTI Indicators (IOB, IOC) signature, permissions-required
- CVE-2026-121517 | CVE Analysis and Report third-party-advisory
- Submit #1018543 | IrfanView 4.76.0.0 (x64) Heap-based Buffer Overflow third-party-advisory
- https://github.com/dwBruijn/CVEs/blob/main/IrfanView/TIFF/Tiff_Wang.md exploit
- https://www.irfanview.com/ product