CVE-2026-47631
HIGH 8.1Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
ELEVATED IMPACT
Severe if exploited (CVSS 8.1), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 27th percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
8.1CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ⚠User interaction: A user must take an action (click / open a file)
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
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
Weakness (CWE)
- CWE-79: Cross-site scripting (XSS)
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C