CyberSecBulletin
CVE-2026-49241NVD status: Analyzed

angular: Improper Neutralization of Input During Web Page Generation

Published Updated By the CyberSecBulletin desk

CVE-2026-49241 is a high-severity improper neutralization of input during web page generation vulnerability in angular, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected angular versions: < 21.2.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Angular Language Service to 21.2.4 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Angularangular< 21.2.4Not stated
AngularAngular Language Servicebefore 21.2.421.2.4

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.08.7HighCNA (github.com)
CVSS 3.18.8HighNVD

Official description

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) 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Input During Web Page Generation

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

How developers prevent this class of flaw

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
  • Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Input During Web Page Generation vulnerabilities (CWE-79)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in angular

All angular vulnerabilities

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