# CVE-2026-118147: Microsoft Visual Studio improper certificate validation spoofing

Source: https://junglewise.ai/threats/cve-2026-118147-improper-certificate-validation-in-visual-studio-allows-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-31. Updated: 2026-10-31  
License: CC BY 4.0 with a link back

CVE-2026-118147 · Severity: high · CVSS 7.4 · Published 2026-10-31

Microsoft Visual Studio contains a flaw that fails to properly validate certificates, allowing an attacker to impersonate legitimate servers or services over a network. An attacker could use this to perform spoofing attacks, potentially redirecting developers to malicious servers or intercepting communications meant for legitimate services, leading to credential theft or malware distribution.

Technologies: [Microsoft Visual Studio](https://junglewise.ai/threats/technologies/visual-studio). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-118147 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-118147 being exploited in the wild.

**How severe is CVE-2026-118147?** High severity, with a CVSS score of 7.4, published 31 October 2026.

**Which products and versions are affected?** Microsoft Visual Studio.

**Is there a fix for CVE-2026-118147?** 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-2026-118147 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-118147?** Check whether you run Microsoft Visual Studio. 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

Visual Studio fails to properly validate X.509 certificates during network communications, enabling attackers to perform man-in-the-middle spoofing attacks without valid credentials. The vulnerability requires network access but does not require authentication or user interaction beyond normal use of the application. An attacker can impersonate trusted services to intercept or redirect traffic from the IDE.

## Affected products

- Microsoft Visual Studio

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-118147](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-118147)

## Related threats

- [Microsoft Visual Studio heap buffer overflow RCE](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-224be73b)
- [Microsoft Visual Studio heap-based buffer overflow](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-6a4b9d28)
- [Microsoft Visual Studio deserialization remote code execution](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-1eb2f932)
- [Microsoft Visual Studio stack-based buffer overflow](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-d956164d)
- [Microsoft Visual Studio heap buffer overflow RCE](https://junglewise.ai/threats/cve-2026-118745-heap-based-buffer-overflow-in-visual-studio-allows-an)