Full Report
Microsoft Edge security advisory (AV26-293)
Analysis Summary
# Vulnerability: Microsoft Edge Multiple Security Vulnerabilities (AV26-293)
## CVE Details
- **CVE ID:** CVE-2026-21588 (and potentially others integrated from the Chromium project)
- **CVSS Score:** 8.3 (High) - *Estimate based on typical browser RCE vulnerabilities; specific scores vary by CVE.*
- **CWE:** Commonly includes CWE-416 (Use After Free), CWE-122 (Heap-based Buffer Overflow), and CWE-125 (Out-of-bounds Read).
## Affected Systems
- **Products:** Microsoft Edge (Chromium-based)
- **Versions:** All versions prior to 146.0.3856.84
- **Configurations:** Systems utilizing the Stable Channel of Microsoft Edge on Windows, macOS, and Linux.
## Vulnerability Description
This advisory covers multiple security flaws resolved in the latest Chromium-based Edge update. While specific technical deep-dives for each sub-CVE are typically released post-patch, these vulnerabilities generally involve memory corruption issues within the V8 JavaScript engine or the Mojo IPC framework. These flaws allow for arbitrary code execution or sandboxed escapes when the browser processes specially crafted web content.
## Exploitation
- **Status:** Not exploited (No reports of active exploitation in the wild for this specific version at the time of release).
- **Complexity:** Low to Medium.
- **Attack Vector:** Network (Remote/Web-based).
## Impact
- **Confidentiality:** High (Potential to access cookies, saved credentials, and session data).
- **Integrity:** High (Potential for unauthorized modification of system files or browser settings).
- **Availability:** High (Potential for application crashes or system instability).
## Remediation
### Patches
- **Microsoft Edge Stable Channel:** Update to version **146.0.3856.84** or later.
### Workarounds
- There are no official functional workarounds. The primary mitigation is the application of the security update. Users should avoid visiting untrusted or suspicious websites until the update is applied.
## Detection
- **Indicators of compromise:** Unusual browser crashes, unexpected outbound network traffic to unknown IPs, or unauthorized changes to browser extensions/settings.
- **Detection methods and tools:**
- Vulnerability scanners (e.g., Nessus, Qualys) can identify outdated versions of `msedge.exe`.
- Microsoft Endpoint Configuration Manager (MECM) or Intune can be used to audit versioning across the enterprise.
## References
- **Vendor Advisory:** hxxps[://]learn[.]microsoft[.]com/en-us/DeployEdge/microsoft-edge-relnotes-security#march-26-2026
- **Canadian Centre for Cyber Security:** hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/microsoft-edge-security-advisory-av26-293