Cyber Resilience

CVE-2026-49241

HighRCE

Published: 22 June 2026

Published
22 June 2026
Modified
26 June 2026
KEV Added
Patch
CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0015 4.9th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-49241 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Angular Angular Language Service. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Supply Chain Compromise (T1195); ranked at the 4.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

The Angular Language Service VS Code Extension provides a rich editing experience for Angular templates. Prior to 21.2.4, the client-side Angular Language Service VS Code extension reads the custom TypeScript SDK paths typescript.tsdk and js/ts.tsdk.path directly from workspace configurations (.vscode/settings.json)…

more

without verifying VS Code Workspace Trust state or asking for user consent (located in client/src/client.ts). The client-side extension then passes the parsed settings path as a command-line argument (--tsdk) to the background Node.js language server process. During server initialization, the background language server resolves and dynamically imports (via standard Node.js require()) the module library tsserverlibrary.js relative to the workspace-specified custom directory path. An attacker can exploit this behavior by committing a repository containing a local malicious tsserverlibrary.js script inside a custom folder, and a crafted .vscode/settings.json file pointing to that folder. When a developer opens the repository folder in VS Code, the extension automatically attempts to initialize and load the server, which dynamically resolves, loads, and executes the malicious script silently in the background. This vulnerability is fixed in 21.2.4.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
T1195.001 Compromise Software Dependencies and Development Tools Initial Access
Adversaries may manipulate software dependencies and development tools prior to receipt by a final consumer for the purpose of data or system compromise.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
Why these techniques?

Vuln enables supply-chain attack (malicious JS committed to repo/workspace) that results in automatic client-side execution of attacker-controlled JavaScript via Node require() when the workspace is opened.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

angular
angular language service
≤ 21.2.4

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79 CWE-94

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-494

Policies can require integrity verification of software prior to installation, reducing risks from unverified downloads.

addresses: CWE-494

Blocks installation of components lacking a valid signature, mitigating download or installation of code without integrity checks.

addresses: CWE-494

Acquisition and maintenance portions of the strategy drive requirements for integrity verification of downloaded or supplied code.

addresses: CWE-494

Mandating integrity control and approved-only changes during development prevents incorporation of code or components lacking integrity validation.

addresses: CWE-494

Supply chain protection requires integrity verification of acquired components, directly reducing insertion or tampering of malicious code during delivery.

addresses: CWE-494

Reduces exposure to code obtained without integrity verification by requiring assurance processes that confirm authenticity and absence of tampering.

References