Description
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. From 1.20.0 until 1.21.1, the Angular DevTools background service worker accepts chrome.runtime.sendMessage runtime messages from untrusted web pages or third-party content scripts without adequately verifying the message source. An untrusted sender that obtains a valid randomized victim tabId can direct the extension to use chrome.debugger to attach to another browser tab and trigger Chrome DevTools Protocol breakpoints. This can display the debugging banner, pause JavaScript execution, and prevent interaction with the target tab, but it does not provide remote code execution, privilege escalation, or cross-origin access to memory or credentials. This issue is fixed in version 1.21.1.
References5
Metrics
- CVSS 4.0
-
5.1
MEDIUM
Score source: CNA
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:H/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 — exploit probability
- 0% percentile: 29 · as of 11 November 2026
- CWE
- CWE-346CWE-441CWE-940
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.