Buffer overflow in Irfanview
CVE-2026-121517
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".
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Irfanview — versions 4.76.0.0
Weakness classification (CWE)
References
- github.com/dwBruijn/CVEs/blob/main/IrfanView/TIFF/Tiff_Wang.md (exploit)
- vuldb.com/cve/CVE-2026-121517 (third-party-advisory)
- vuldb.com/submit/1018543 (third-party-advisory)
- vuldb.com/vuln/430288 (vdb-entry)
- vuldb.com/vuln/430288/cti (signature, permissions-required)
- www.irfanview.com/ (product)
Frequently asked questions
- What is CVE-2026-121517?
- CVE-2026-121517 is a medium-severity vulnerability in Irfanview, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.0/10. Published 2026-11-03.
- How severe is CVE-2026-121517?
- Medium severity. CVSS v3 base score is 5.0 out of 10.