CVE-2026-96940
HIGH 8.8Weak authentication in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
Severe if exploited (CVSS 8.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
2.7%chance of exploitation in 30 days · 86th percentile
Impact if exploited
8.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓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.
Search for new PoCs
Search GitHub now — results may be empty or unverified.
Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Data snapshot:
Affected
Vendors Microsoft
Products Microsoft Exchange Server 2016 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 14 Microsoft Exchange Server 2019 Cumulative Update 15 Microsoft Exchange Server Subscription Edition Rtm Exchange Server Exchange Server Subscription Edition
Weakness (CWE)
- CWE-1390: : Weak Authentication
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
References and research data (JSON)
Unverified PoC candidates
Catalogue matches for further research. These repositories have not been validated as working exploits.
1 candidate
- https://github.com/HORKimhab/CVE-2026-96940
CVE-2026-96940
PoC-in-GitHub · CVE-2026-96940
PoC-in-GitHub · CVE-2026-96940 · Updated 2026-10-06T08:04:35Z
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Microsoft | Exchange Server | 2016 |
| Microsoft | Exchange Server | 2019 |
| Microsoft | Exchange Server | 2019 |
| Microsoft | Exchange Server Subscription Edition | < 15.02.2562.053 |
All CVSS metrics
- HIGH 8.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - HIGH 8.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Patches & mitigations
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96940 CVE record · microsoft · Updated 2026-10-25T18:43:48.396Z
NVD · CVE-2026-96940 · Updated 2026-10-15T02:35:54.010
Advisories
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-91771 EUVD · EUVD-2026-91771