CVE-2025-21355
Microsoft Bing Remote Code Execution Vulnerability
Missing Authentication for Critical Function in Microsoft Bing allows an unauthorized attacker to execute code over a network
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Microsoft Bing Remote Code Execution Vulnerability
Missing Authentication for Critical Function in Microsoft Bing allows an unauthorized attacker to execute code over a network
- Record
CVE-2025-21355- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N/E:P/RL:O/RC:C - Weakness
- CWE-306
- Updated
- 2026-11-02
EUVDEUVD-2025-4643
Missing Authentication for Critical Function in Microsoft Bing allows an unauthorized attacker to execute code over a network
- Record
EUVD-2025-4643- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N/E:P/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-fx4j-9fqf-p9p2
Missing Authentication for Critical Function in Microsoft Bing allows an unauthorized attacker to...
Missing Authentication for Critical Function in Microsoft Bing allows an unauthorized attacker to execute code over a network
- Record
GHSA-fx4j-9fqf-p9p2- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
NVD
Missing Authentication for Critical Function in Microsoft Bing allows an unauthorized attacker to execute code over a network
- Record
CVE-2025-21355- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-306
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-21355 is a high vulnerability (CVSS 8.6) in Microsoft Bing, published February 19, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.69%, the 77th percentile. No source names a fixed version.