CVE-2026-62873
CRITICAL 9.8 ALL-YEARSImproper verification of cryptographic signature in Microsoft 365 Admin Center allows an unauthorized attacker to elevate privileges over a network.
Severe if exploited (CVSS 9.8), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.6%chance of exploitation in 30 days · 49th percentile
Impact if exploited
9.8CVSS 3.1 · CRITICAL · CNA
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Weakness (CWE)
- CWE-347: : Improper Verification of Cryptographic Signature
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
References and research data (JSON)
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | Windows Admin Center | * |
All CVSS metrics
- CRITICAL 9.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - CRITICAL 9.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
Patches & mitigations
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62873 CVE record · microsoft · Updated 2026-10-21T20:51:11.202Z
NVD · CVE-2026-62873 · Updated 2026-10-24T16:10:00.153
Advisories
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-54326 EUVD · EUVD-2026-54326
Sources: NVD · CVE.org · All sources and attribution · EPSS