High severity · published May 12, 2026
CVE-2026-42498
Apache Tomcat: WebSocket authentication header exposure
7.3
CVSS
0.6%
EPSS
No
On KEV
Description
Exposure of HTTP Authentication Header to unexpected hosts during WebSocket authentication vulnerability in Apache Tomcat.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.2 through 9.0.117, from 8.5.24 through 8.5.100, from 7.0.83 through 7.0.109.
Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118, which fix the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 51% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TO
Tomcat · Apache
11.0.0-M1 through 11.0.21; 10.1.0-M1 through 10.1.54; 9.0.2 through 9.0.117; 8.5.24 through 8.5.100; 7.0.83 through 7.0.109 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42498
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42498
Mailing List
https://lists.apache.org/thread/n61zwf75jrv09rz90j4jssncm244bwdb
Mailing List
http://www.openwall.com/lists/oss-security/2026/05/12/14
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