CRITICAL CWE-79
CVE-2026-55008
Microsoft Exchange Server Spoofing Vulnerability
Microsoft·Exchange Server 2016 Cumulative Update 23
9.6/ 10
CVSS 3.1
Critical severity
0.86%
EPSS exploit odds
Chance of exploitation in the next 30 days
Higher than 59% of all CVEs
Not listed
CISA KEV catalog
No confirmed in-the-wild exploitation on CISA's list.
Timeline
- Published
- Jul 14, 2026
- Updated
- Nov 1, 2026
- First covered
- Jul 14, 2026
- Latest story
- 4 months ago
Summary
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Attack profile
Attack vectorNetwork
ComplexityLow
PrivilegesNone
User interactionRequired
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:CAffected products
- Microsoft Exchange Server 2016 Cumulative Update 2315.01.0.0 to before 15.01.2507.071
- Microsoft Exchange Server 2019 Cumulative Update 1415.02.0.0 to before 15.02.1544.043
- Microsoft Exchange Server 2019 Cumulative Update 1515.02.0.0 to before 15.02.1748.048
- Microsoft Exchange Server Subscription Edition RTM15.02.0.0 to before 15.02.2562.045