Critical severity · published Sep 23, 2026
CVE-2026-76183
Apache Tomcat: Bypass of security constraints for WebSocket endpoints
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
Authentication Bypass by Alternate Name vulnerability in Apache Tomcat allowed the security constraints for any WebSocket endpoint to be bypassed.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121.
The following versions were EOS at the time the CVE was created but are
known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through 7.0.109. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% 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 11.0.25; 10.1.0-M1 through 10.1.59; 9.0.0.M1 through 9.0.121; 8.5.0 through 8.5.100; 7.0.43 through 7.0.109 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-76183
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-76183
vendor-advisory
https://lists.apache.org/thread/45mxk8nj2q8pkhct6lfxkvtm2jpywrsp
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