Apache Tomcat Vulnerabilities: Latest CVEs and Version Check

Apache Tomcat Security in Short

Tomcat runs Java web apps. Several release lines are supported at once, and each gets fixes in its own releases. Tomcat flaws are often exploited within days of release, especially ones in partial PUT requests, session handling and the manager app.

How to Keep Tomcat Patched

Update to the latest release in your line. Tomcat is often installed by hand, so it won't update with the rest of the system.
Remove the example apps and the manager app if you don't use them, or limit who can reach them.
Check apps that bundle Tomcat (Spring Boot and many vendor products): they need their own update.

The Past Eight Weeks

20 flaws, newest first.

20 Oct 2026 asynchronous servlets · Race condition Incorrect object recycling and re-use vulnerability in Apache Tomcat affecting HTTP/2 processing of asynchron… CVE-2026-101356 9.1

Incorrect object recycling and re-use vulnerability in Apache Tomcat affecting HTTP/2 processing of asynchronous servlets can trigger request and/or response mix-up between users. This issue affects Apache Tomcat: from 11.0.22 through 11.0.26, from 10.1.55 through 10.1.60, from 9.0.118 through 9.0.122. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fixes the issue.

Patch now · NVD Record

20 Oct 2026 Apache Tomcat meant · Memory corruption Buffer under-read vulnerability in Apache Tomcat meant that a large non-blocking write could result in the re… CVE-2026-103119 9.1

Buffer under-read vulnerability in Apache Tomcat meant that a large non-blocking write could result in the response body being split between the current request and the next request received on that connection leading most likely to failure of the second request and possibly leakage of data from the first response to the second. This issue affects Apache Tomcat: from 11.0.0-M25 through 11.0.26. Users are recommended to upgrade to version 11.0.27, which fixes the issue.

Patch now · NVD Record

20 Oct 2026 Authentication bypass A missing critical step in authentication vulnerability in Apache Tomcat when the JNDI realm was configured w… CVE-2026-101296 8.1

A missing critical step in authentication vulnerability in Apache Tomcat when the JNDI realm was configured with with a non GSSAPI SASL authentication mechanism allowed attackers to authenticate without providing the correct password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.26, from 10.1.0-M1 through 10.1.60, from 9.0.0.M1 through 9.0.122. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fix the issue.

Patch this week · NVD Record

20 Oct 2026 Race condition Time-of-check time-of-use (TOCTOU) race condition vulnerability in Apache Tomcat when creating unix domain so… CVE-2026-80353 8.1

Time-of-check time-of-use (TOCTOU) race condition vulnerability in Apache Tomcat when creating unix domain sockets for the APR/Native connector allows an unauthorised local user to access the unix domain socket. The fix for CVE-2026-65183 only addressed the NIO connector. It did not address the same issue in the APR/Native connector. This issue affects Apache Tomcat: from 9.0.47 through 9.0.122. Users are recommended to upgrade to version 9.0.123, which fixes the issue.

Patch this week · NVD Record

20 Oct 2026 Apache Tomcat allowed an trailer information · Security flaw Incomplete cleanup vulnerability in Apache Tomcat allowed an trailer information from a previous request to l… CVE-2026-88041 7.5

Incomplete cleanup vulnerability in Apache Tomcat allowed an trailer information from a previous request to leak into a subsequent request. This issue affects Apache Tomcat: from 11.0.0-M23 through 11.0.26, from 10.1.27 through 10.1.60, from 9.0.92 through 9.0.122. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fix the issue.

Patch this week · NVD Record

20 Oct 2026 Security flaw Incomplete cleanup vulnerability in Apache Tomcat could cause TLS 1.3 connections to fail intermittently. CVE-2026-93446 7.5

Incomplete cleanup vulnerability in Apache Tomcat could cause TLS 1.3 connections to fail intermittently. This issue affects Apache Tomcat: from 11.0.0-M21 through 11.0.26, from 10.1.25 through 10.1.60, from 9.0.90 through 9.0.122. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fix the issue.

Patch this week · NVD Record

20 Oct 2026 Security flaw Not Failing Securely ('Failing Open') vulnerability in Apache Tomcat. CVE-2026-74048 6.5

Not Failing Securely ('Failing Open') vulnerability in Apache Tomcat. If the OpenSSLLifecycleListener is configured to use FIPS mode but FIPS activation fails, Tomcat logs and error but continues to use JSSE in non-FIPS mode with the provided configuration. This issue affects Apache Tomcat: from 11.0.0-M14 through 11.0.26, from 10.1.22 through 10.1.60, from 9.0.92 through 9.0.122. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fix the issue.

Keep an eye · NVD Record

20 Oct 2026 Security flaw Execution After Redirect (EAR) vulnerability in Apache Tomcat. CVE-2026-74049 6.1

Execution After Redirect (EAR) vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.26, from 10.1.0-M1 through 10.1.60, from 9.0.0.M1 through 9.0.122. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.27, 10.1.61, 9.0.123, which fixes the issue.

Keep an eye · NVD Record

23 Sep 2026 Authentication bypass Authentication Bypass by Alternate Name vulnerability in Apache Tomcat allowed the security constraints for a… CVE-2026-76183 9.8

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.

Patch now · NVD Record

23 Sep 2026 Authentication bypass CLIENT_CERT authentication does not fail as expected for some scenarios when soft fail is disabled vulnerabil… CVE-2026-86248 9.8

CLIENT_CERT authentication does not fail as expected for some scenarios when soft fail is disabled vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M14 through 11.0.25, from 10.1.22 through 10.1.59, from 9.0.92 through 9.0.121. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

Patch now · NVD Record

23 Sep 2026 fix for CVE-2026-41293 · Input validation flaw Inconsistent interpretation of HTTP/2 requests ('HTTP Request/Response smuggling') vulnerability in Apache To… CVE-2026-86350 9.1

Inconsistent interpretation of HTTP/2 requests ('HTTP Request/Response smuggling') vulnerability in Apache Tomcat caused by a regression in fix for CVE-2026-41293 can trigger request header mix-up. This issue affects Apache Tomcat: from 11.0.22 through 11.0.25, from 10.1.55 through 10.1.59, from 9.0.118 through 9.0.121. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

Patch now · NVD Record

23 Sep 2026 Race condition Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in … CVE-2026-77762 8.1

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.39 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.

Patch this week · NVD Record

23 Sep 2026 WebSocket close message enabled a DoS attack · Denial of service Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message en… CVE-2026-77791 7.5

Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack. This issue affects Apache Tomcat: from 11.0.0-M5 through 11.0.25, from 10.1.8 through 10.1.59, from 9.0.74 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.88 through 8.5.100. 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.

Patch this week · NVD Record

23 Sep 2026 Denial of service Allocation of resources without limits or throttling vulnerability in Apache Tomcat allows an unauthenticated… CVE-2026-78383 7.5

Allocation of resources without limits or throttling vulnerability in Apache Tomcat allows an unauthenticated AJP request to pin an AJP processing thread leading to denial of service. 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 EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.0 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.

Patch this week · NVD Record

23 Sep 2026 Denial of service Missing release of resource after effective lifetime, Comparison using wrong factors vulnerability in Apache … CVE-2026-79677 7.5

Missing release of resource after effective lifetime, Comparison using wrong factors vulnerability in Apache Tomcat allows a denial of service as a result of lost time outs for asynchronous WebSocket writes. 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 EOL 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.

Patch this week · NVD Record

23 Sep 2026 Security flaw Improper handling of length parameter inconsistency vulnerability in Apache Tomcat allows WebSocket message s… CVE-2026-87022 7.5

Improper handling of length parameter inconsistency vulnerability in Apache Tomcat allows WebSocket message smuggling when per-message-deflate is used. 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 7.0.56 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 9.1.22, which fix the issue.

Patch this week · NVD Record

23 Sep 2026 Authentication bypass Improper Authentication vulnerability in Apache Tomcat. CVE-2026-75973 7.3

Improper Authentication vulnerability in Apache Tomcat. When Jakarta Authentication was configured with SimpleAuthConfigProvider as the default provider and multiple web application used that provider, the realm for the first web application to authenticate a request would be used for all web applications. 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.M4 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fixes the issue.

Patch this week · NVD Record

23 Sep 2026 Security flaw Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timin… CVE-2026-78437 7.3

Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail. This issue affects Apache Tomcat: from 11.0.19 through 11.0.25, from 10.1.53 through 10.1.59, from 9.0.116 through 9.0.121. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

Patch this week · NVD Record

23 Sep 2026 Security flaw Improper Check for Certificate Revocation vulnerability in Apache Tomcat. CVE-2026-73581 6.5

Improper Check for Certificate Revocation vulnerability in Apache Tomcat. Both the OpenSSL and OpenSSL-FFM TLS implementations ignore CRLs when certificate uses a keystore. 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 EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.59, 9.0.122, which fixes the issue.

Keep an eye · NVD Record

23 Sep 2026 Input validation flaw Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomc… CVE-2026-77756 3.7

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. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.47 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.67 through 8.5.100. 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.

Keep an eye · NVD Record

Being Exploited

Apache Tomcat flaws CISA has added to its list of flaws attackers are using in the past six months, newest first. See all 6 on the KEV page.

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Apache Tomcat

Missing Encryption of Sensitive Data vulnerability in Apache Tomcat due to the fix for CVE-2026-29146 allowing the bypass…

Score 7.5 / 10 · Being exploited

CVE-2026-34486