Apache Tomcat up to 11.0.21 improper authorization

Summaryinfo

A vulnerability identified as critical has been detected in Apache Tomcat up to 11.0.21. This affects an unknown part. Performing a manipulation results in improper authorization. This vulnerability is reported as CVE-2026-43515. The attack is possible to be carried out remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Apache Tomcat up to 11.0.21. It has been classified as critical. This affects some unknown functionality. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Improper Authorization vulnerability when multiple method constraints define an HTTP method for the same extension 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 9.0.0.M1 through 9.0.117, from 8.5.0 through 8.5.100, from 7.0.0 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.

The advisory is shared at lists.apache.org. This vulnerability is uniquely identified as CVE-2026-43515 since 05/01/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/29/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 314335 (Apache Tomcat 10.1.0.M1 < 10.1.55 multiple vulnerabilities), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 9.0.118, 10.1.55 or 11.0.22 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (314335) and CERT Bund (WID-SEC-2026-2308). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• SAP Software

Productinfo

Type

• Application Server Software

Vendor

• Apache

Name

• Tomcat

Version

• 6.x
• 7.0.109
• 8.0
• 8.1
• 8.2
• 8.3
• 8.4
• 8.5.100
• 9.0.117
• 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
• 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

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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