CVE-2026-121660: Visual Studio Code Security Feature Bypass Vulnerability
CVE-2026-121660 is a security feature bypass vulnerability in Visual Studio Code, rated Important by Microsoft, with a CVSS 3.1 base score of 7.5 (High). An attacker can exploit it remotely over the network, without any privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday. It affects 1 product in 1 product family (Developer Tools).
Key facts
- CVE ID
- CVE-2026-121660
- Severity
- High CVSS 7.5
- Microsoft severity
- Important
- Impact
- Security Feature Bypass
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Developer Tools
CVSS score and vector
Microsoft scores CVE-2026-121660 at 7.5 (temporal 6.5) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Incomplete list of disallowed inputs in Visual Studio Code allows an unauthorized attacker to bypass a security feature over a network.
Frequently asked questions (Microsoft)
What security feature could be bypassed by successfully exploiting this vulnerability?
Successful exploitation could allow an extension to be installed and run despite an administrator's extension allowlist policy. The user must be convinced to install the extension.
Why is the attack complexity rated High?
Successful exploitation through the extension marketplace requires the attacker to control a publishing identity that meets specific conditions. Obtaining that identity is a prerequisite beyond simply creating a malicious extension.
Affected products (1)
Developer Tools
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Visual Studio Code | Release Notes | Security Update | 1.145.3 |
Acknowledgments
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |