CVE-2026-42897

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2026-05-15. Federal remediation due 2026-05-29.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

70.66% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 99.3% of scored records. A rank, not a probability.

NVD base score

6.1 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

NVD analysis status

Analyzed. NVD last modified this record on 2026-10-26.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-05-14 17:00Z5 MO AGO

Last updated

2026-08-10 15:14Z2 MO AGO

Reserved

2026-04-30

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

High (CVSS 8.1)

CNA CVSS vector

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

Weaknesses

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base

Data version

5.2

Document digest

c1d726df940c5bbb23bb7d807beaa1f1adc77bdf231456d2e30b8715e5a404e9

• msrc.microsoft.comMicrosoft Exchange Server Spoofing Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42897vendor-advisorypatch
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-42897government-resource