CVE-2026-42897
Microsoft Exchange Server Spoofing Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Microsoft Exchange Server Spoofing Vulnerability
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.
- Record
CVE-2026-42897- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-30343
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.
- Record
EUVD-2026-30343- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-3c39-338m-m4vp
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft...
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.
- Record
GHSA-3c39-338m-m4vp- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CISA KEV No score
Microsoft Exchange Server Cross-Site Scripting Vulnerability
Microsoft Exchange Server contains a cross-site scripting vulnerability during web page generation in Outlook Web Access and when certain interaction conditions are met, arbitrary JavaScript can be executed in the browser context.
- Record
CVE-2026-42897- Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-42897- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | atiilla/CVE-2026-42897 | 2026-05-15 |
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation | ||
| first indexed | CVE List, EUVD, GitHub Advisories, CISA KEV, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-42897 is a high vulnerability (CVSS 8.1) in Microsoft Exchange Server, published May 14, 2026. CISA lists it as known to be exploited, since May 15, 2026. EUVD reports exploitation since May 15, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 70.7%, the 99th percentile. No source names a fixed version.