Apache Tomcat up to 8.5.100/9.0.121/10.1.59/11.0.25 improper authentication

Summaryinfo

A vulnerability described as critical has been identified in Apache Tomcat up to 8.5.100/9.0.121/10.1.59/11.0.25. Affected is an unknown function. The manipulation results in improper authentication. This vulnerability is cataloged as CVE-2026-75973. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in Apache Tomcat up to 8.5.100/9.0.121/10.1.59/11.0.25. Affected is an unknown code block. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at lists.apache.org. This vulnerability is traded as CVE-2026-75973 since 08/18/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/24/2026).

Upgrading to version 9.0.122, 10.1.60 or 11.0.26 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3527). Once again VulDB remains the best source for vulnerability data.

Affected

• Apache Tomcat

Productinfo

Type

• Application Server Software

Vendor

• Apache

Name

• Tomcat

Version

• 8.0
• 8.1
• 8.2
• 8.3
• 8.4
• 8.5.100
• 9.0.121
• 10.1.0
• 10.1.1
• 10.1.2
• 10.1.3
• 10.1.4
• 10.1.5
• 10.1.6
• 10.1.7
• 10.1.8
• 10.1.9
• 10.1.10
• 10.1.11
• 10.1.12
• 10.1.13
• 10.1.14
• 10.1.15
• 10.1.16
• 10.1.17
• 10.1.18
• 10.1.19
• 10.1.20
• 10.1.21
• 10.1.22
• 10.1.23
• 10.1.24
• 10.1.25
• 10.1.26
• 10.1.27
• 10.1.28
• 10.1.29
• 10.1.30
• 10.1.31
• 10.1.32
• 10.1.33
• 10.1.34
• 10.1.35
• 10.1.36
• 10.1.37
• 10.1.38
• 10.1.39
• 10.1.40
• 10.1.41
• 10.1.42
• 10.1.43
• 10.1.44
• 10.1.45
• 10.1.46
• 10.1.47
• 10.1.48
• 10.1.49
• 10.1.50
• 10.1.51
• 10.1.52
• 10.1.53
• 10.1.54
• 10.1.55
• 10.1.56
• 10.1.57
• 10.1.58
• 10.1.59
• 11.0.0
• 11.0.1
• 11.0.2
• 11.0.3
• 11.0.4
• 11.0.5
• 11.0.6
• 11.0.7
• 11.0.8
• 11.0.9
• 11.0.10
• 11.0.11
• 11.0.12
• 11.0.13
• 11.0.14
• 11.0.15
• 11.0.16
• 11.0.17
• 11.0.18
• 11.0.19
• 11.0.20
• 11.0.21
• 11.0.22
• 11.0.23
• 11.0.24
• 11.0.25

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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