CVE-2025-33051: Microsoft Exchange Server 2016 Cumulative Update 23 · Information Exposure
Affects Microsoft Exchange Server 2016 Cumulative Update 23Source CVE Database V5
Not known to be exploited · CVSS 7.5 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 1.2% chance of exploitation in 30 days – higher than 69% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 12 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Microsoft Exchange Server 2016 Cumulative Update 23 | Affected
| Fixed in– |
AI-suggested
1. Monitor Microsoft security advisories closely and apply official patches or cumulative updates as soon as they become available to remediate the vulnerability. 2. Until patches are released, restrict external network access to Exchange Server 2016 instances by implementing strict firewall rules and network segmentation to limit exposure. 3. Employ network intrusion detection and prevention systems (IDS/IPS) to detect anomalous traffic patterns indicative of exploitation attempts targeting Exchange servers. 4. Conduct regular audits of Exchange Server configurations and logs to identify any unusual access or information disclosure activities. 5. Implement strict access controls and multi-factor authentication for administrative interfaces to reduce the risk of lateral movement if information is leaked. 6. Educate IT staff about the vulnerability and encourage prompt incident reporting and response readiness. 7. Consider deploying web application firewalls (WAFs) with custom rules to block suspicious requests targeting known Exchange Server endpoints. 8. Review and limit the amount of sensitive information stored or accessible through Exchange Server to minimize potential exposure.
Description
Exposure of sensitive information to an unauthorized actor in Microsoft Exchange Server allows an unauthorized attacker to disclose information over a network.