Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:NSummary
CVE-2025-21279 is a medium-severity Type Confusion (CWE-843) vulnerability in Microsoft Edge Chromium. Its CVSS base score is 6.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 27% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Microsoft Edge (Chromium-based) contains a remote code execution vulnerability tracked as CVE-2025-21279. The flaw is associated with CWE-843 and carries a CVSS 3.1 base score of 6.5, reflecting a network-attack vector that requires low complexity, no privileges, and only user interaction to trigger high-impact confidentiality loss while leaving integrity and availability unaffected.
An unauthenticated remote attacker can exploit the issue by convincing a user to visit a specially crafted web page or resource in Microsoft Edge. Successful exploitation allows the attacker to execute arbitrary code in the context of the current user, primarily resulting in unauthorized disclosure of sensitive information from the affected browser process.
The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21279 provides official guidance on available updates and mitigation steps for the affected Edge versions.
EPSS scores for the CVE remain low, with a current value of 0.0091 and a recorded peak of 0.0146.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2344
Vulnerability Data
Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including fuzzing and type-aware analysis) directly finds type-confusion flaws before deployment.
Engineering principles can require use of type-safe languages, static typing, and runtime type checks that structurally avoid allocating one type and accessing another.
Memory-protection controls limit the blast radius when a type-confusion access occurs but do not stop the flaw itself.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent type-confusion flaws via safe typing, static analysis, and code review while the control itself addresses many additional weaknesses.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect type-confusion vulnerabilities through fuzzing and static analysis.
Secure SDLC mandates type-safe design and review that can catch type-confusion flaws.
Application security requirements can specify strong typing and interface contracts that reduce type confusion.
Secure architecture principles promote type-safe languages and memory-safety mechanisms that mitigate type confusion.
Secure coding standards directly forbid unsafe type casts and require static-analysis checks for type confusion.