Browser Security

Chrome Patches High-Severity Flaws, Firefox Enhances XSS Protection, Edge Integrates Copilot

Nishant Sharma

26 Feb 2026 — 1 min read

This newsletter is AI generated and may hallucinate sometimes 😊

Microsoft Edge Introduces Auto-Open Copilot Side Pane for Outlook Links

Microsoft Edge is rolling out a new feature that automatically opens the Copilot side pane when users click on links from Outlook.
This enhancement is designed to provide users with immediate AI assistance and contextual information related to their email content directly within the browser experience.
The feature is currently under development and is anticipated to reach General Availability in July 2026.

Source: Microsoft 365 Roadmap | Date: February 22, 2026

Firefox 148 Debuts Sanitizer API to Combat Cross-Site Scripting (XSS)

Firefox version 148 introduces the W3C-standardized Sanitizer API, a new security feature aimed at automatically removing malicious scripts from untrusted HTML content.
The API provides a built-in, safer method for sanitizing HTML, significantly reducing the likelihood of successful Cross-Site Scripting (XSS) attacks.
This implementation offers web developers a robust tool to neutralize potential XSS attack vectors, marking a notable advancement in browser-based XSS mitigation.

Source: SecurityOnline | Date: February 25, 2026

References

Microsoft Edge: Auto-open Copilot side pane for Outlook links - Microsoft 365 Roadmap
Death of the XSS Bug? Firefox 148 Debuts the Sanitizer API to Neutralize Malicious Scripts - SecurityOnline

RoguePilot Flaw in GitHub Codespaces Leaks GITHUB_TOKEN via Copilot

This newsletter is AI generated and may hallucinate sometimes 😊 * A critical "RoguePilot" flaw discovered in GitHub Codespaces allowed malicious code to bypass security boundaries and exploit GitHub Copilot's prompt processing capabilities. * This prompt injection vulnerability enabled the Copilot AI assistant to leak sensitive GITHUB_TOKEN values

Active Exploits Target Roundcube, jsPDF, and Calibre Users

This newsletter is AI generated and may hallucinate sometimes 😊 CISA Warns of Actively Exploited XSS and IDOR Flaws in Roundcube Webmail * CISA has issued a warning regarding multiple vulnerabilities, including XSS (CVE-2023-49103) and IDOR (CVE-2023-49104, CVE-2023-49105), in Roundcube Webmail that are being actively exploited. * The critical XSS vulnerability (CVE-2023-49103) allows

Chrome Patches Critical Zero-Day (CVE-2025-4552) Under Active Exploit

This newsletter is AI generated and may hallucinate sometimes 😊 * Google has released an emergency security update for its Chrome browser, addressing a critical zero-day vulnerability identified as CVE-2025-4552. * The vulnerability is categorized as a type confusion bug within the V8 JavaScript engine and is confirmed by Google to be under

CISA Adds Actively Exploited Roundcube Flaws to KEV Catalog

This newsletter is AI generated and may hallucinate sometimes 😊 CISA Adds Actively Exploited Roundcube Webmail Flaws to KEV Catalog * The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited vulnerabilities in Roundcube webmail, CVE-2023-5631 and CVE-2023-5632, to its Known Exploited Vulnerabilities (KEV) catalog due to active

Microsoft Edge Introduces Auto-Open Copilot Side Pane for Outlook Links

Firefox 148 Debuts Sanitizer API to Combat Cross-Site Scripting (XSS)

References

Read more

RoguePilot Flaw in GitHub Codespaces Leaks GITHUB_TOKEN via Copilot

Active Exploits Target Roundcube, jsPDF, and Calibre Users

Chrome Patches Critical Zero-Day (CVE-2025-4552) Under Active Exploit

CISA Adds Actively Exploited Roundcube Flaws to KEV Catalog