CVE-2026-76183
CriticalCVSS 9.8Summary
A vulnerability in Apache Tomcat allows bypassing security constraints for any WebSocket endpoint via an alternate name. Affected versions include 11.0.0-M1 through 11.0.25, 10.1.0-M1 through 10.1.59, and 9.0.0.M1 through 9.0.121. Users are advised to upgrade to 11.0.26, 10.1.60, or 9.0.122.
Risk Assessment
An attacker could bypass security restrictions for WebSockets, potentially leading to unauthorized access or integrity compromise.
Recommendation
Upgrade Apache Tomcat to version 11.0.26, 10.1.60, or 9.0.122 as soon as possible to remediate the issue.
Other vulnerabilities in Apache Tomcat
See all- CVE-2026-87022High
Improper handling of length parameter inconsistency in Apache Tomcat allows WebSocket message smuggling when per-message-deflate is used. Affects versions 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; also known affected: 8.5.0-8.5.100 and 7.0.56-7.0.109.
- CVE-2026-79677High
A vulnerability in Apache Tomcat causes lost timeouts for asynchronous WebSocket writes, leading to denial of service (DoS). The issue affects many Tomcat versions, including 11.0.0-M1 through 11.0.25, 10.1.0-M1 through 10.1.59, and 9.0.0.M1 through 9.0.121.
- CVE-2026-78437High
A vulnerability in Apache Tomcat related to incomplete cleanup can cause a malformed request to potentially (depending on timing) cause one request from another user to fail. Affects versions 11.0.19-11.0.25, 10.1.53-10.1.59, and 9.0.116-9.0.121.
- CVE-2026-78383High
A vulnerability in Apache Tomcat involving uncontrolled resource allocation allows an unauthenticated AJP request to pin an AJP processing thread, leading to denial of service. Affects versions 11.0.0-M1-11.0.25, 10.1.0-M1-10.1.59, and 9.0.0.M1-9.0.121.
- CVE-2026-77791High
A vulnerability in Apache Tomcat involving uncontrolled resource consumption during sending of WebSocket close message enables a DoS attack. Affects versions 11.0.0-M5-11.0.25, 10.1.8-10.1.59, and 9.0.74-9.0.121.
- CVE-2026-77762High
A vulnerability in Apache Tomcat involving a race condition allows an attacker to inject trailer fields into another HTTP/2 request. Affects versions 11.0.0-M1-11.0.25, 10.1.0-M1-10.1.59, and 9.0.39-9.0.121.
- CVE-2026-77756Low
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomcat caused by processing the transfer-encoding header for an HTTP/1.0 request may allow an attacker to cause one request from another user to fail when Tomcat is located behind a reverse proxy. Affects versions: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.47 through 9.0.121. Known affected EOL versions: 8.5.67 through 8.5.100. Recommended upgrade to 11.0.26, 10.1.60 or 9.0.122.
- CVE-2026-75973High
A vulnerability in Apache Tomcat related to improper authentication. When Jakarta Authentication is configured with SimpleAuthConfigProvider as the default provider and multiple web applications use that provider, the realm for the first web application to authenticate a request will be used for all web applications. Affects versions 11.0.0-M1-11.0.25, 10.1.0-M1-10.1.59, and 9.0.0.M4-9.0.121.
- CVE-2026-73581Medium
Apache Tomcat has a vulnerability in certificate revocation checking. OpenSSL and OpenSSL-FFM TLS implementations ignore CRLs when a certificate uses a keystore. Affects versions 11.0.0-M1 through 11.0.25, 10.1.0-M1 through 10.1.58, 9.0.0-M1 through 9.0.121, and 8.5.0 through 8.5.100.
- CVE-2026-43513High
The vulnerability related to improper handling of case sensitivity in LockOutRealm in Apache Tomcat may lead to unauthorized access. It affects versions from 11.0.0-M1 to 11.0.21, from 10.1.0-M1 to 10.1.54, from 9.0.0.M1 to 9.0.117, from 8.5.0 to 8.5.100, and from 7.0.0 to 7.0.109.
Original NVD description (English source)
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.