Heap-based buffer overflow in IrfanView TIFF Wang Annotation handler
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- High
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
IrfanView 4.76.0.0 on Win64 contains a heap-based buffer overflow (CWE-122) in its TIFF Wang Annotation Handler. A remote attacker can trigger it, but the attack complexity is high and the exploitation appears difficult. The vendor states that the TIF-Annotations option is off by default, so normal users are not affected. A public exploit is linked in the references.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Description from the CNA
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".
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | IrfanView | 4.76.0.0 | — | No fix listed | CNA |
- IrfanView Vendor— Affected 4.76.0.0 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for IrfanView.
Written with Claude Haiku 5.5 from the sources below · 2026-11-07
Timeline
- 2026-11-03 Threatist record created from CVE-2026-121517
- 2026-11-03 Alias added: GHSA-99fw-w5ph-h34w
- 2026-11-07 CISA SSVC decision points changed
- 2026-11-07 Priority changed: LOW → MEDIUM
References
Sources
- CVE-2026-121517 · CVE Program
- CVE-2026-121517 · NVD
- FIRST EPSS
- GHSA-99fw-w5ph-h34w · GitHub Advisory Database · CC BY 4.0
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