# CVE-2026-119936: Windows Internet Information Services integer underflow denial of service

Source: https://junglewise.ai/threats/cve-2026-119936-integer-underflow-wrap-or-wraparound-in-windows-internet  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-119936 · Severity: medium · CVSS 5.9 · Published 2026-11-10

An integer underflow vulnerability in Windows Internet Information Services (IIS), a web server that hosts websites and web applications, allows an attacker to crash the service and cause downtime. The vulnerability can be exploited remotely over the network without authentication, disrupting availability for users who depend on the affected server.

Technologies: [Microsoft Windows Internet Information Services](https://junglewise.ai/threats/technologies/windows-internet-information-services). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-119936 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-119936 being exploited in the wild.

**How severe is CVE-2026-119936?** Medium severity, with a CVSS score of 5.9, published 10 November 2026.

**Which products and versions are affected?** Microsoft Windows Internet Information Services.

**Is there a fix for CVE-2026-119936?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-119936 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-119936?** Check whether you run Microsoft Windows Internet Information Services. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An integer underflow (wrap or wraparound) condition exists in Windows Internet Information Services that permits remote denial of service. An unauthenticated attacker over the network can trigger this integer arithmetic error to crash the IIS process, rendering hosted web applications unavailable. A fix is available from Microsoft.

## Affected products

- Microsoft Windows Internet Information Services

## Timeline

- 2026-11-10: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119936](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119936)

## Related threats

- [Microsoft Windows Internet Information Services race condition](https://junglewise.ai/threats/cve-2026-119961-concurrent-execution-using-shared-resource-with-improper)
- [Windows Internet Information Services heap buffer overflow](https://junglewise.ai/threats/cve-2026-78459-heap-based-buffer-overflow-in-windows-internet-information)
- [Microsoft Windows Internet Information Services stack buffer overflow](https://junglewise.ai/threats/cve-2026-70024-stack-based-buffer-overflow-in-windows-internet-information)