CVE-2025-53506

Description

Uncontrolled Resource Consumption vulnerability in Apache Tomcat if an HTTP/2 client did not acknowledge the initial settings frame that reduces the maximum permitted concurrent streams. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.8, from 10.1.0-M1 through 10.1.42, from 9.0.0.M1 through 9.0.106. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Other EOL versions may also be affected. Users are recommended to upgrade to version 11.0.9, 10.1.43 or 9.0.107, which fix the issue.

CVSS Metrics

• v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 1.99%• Percentile: 80%

Techniques & Countermeasures

• CWE-400•Uncontrolled Resource Consumption

  The product does not properly control the allocation and maintenance of a limited resource.

Affected Systems

• apache software foundation•apache tomcat

  ≥ 11.0.0-M1, ≤ 11.0.8 | ≥ 10.1.0-M1, ≤ 10.1.42 | ≥ 9.0.0.M1, ≤ 9.0.106 | ≥ 8.5.0, ≤ 8.5.100

• apache•tomcat

  ≥ 9.0.0, ≤ 9.0.106 | ≥ 10.1.0, ≤ 10.1.42 | ≥ 11.0.0, ≤ 11.0.8

• chainguard•tomcat-10.1

  < 10.1.43-r0

• chainguard•tomcat-10.1-openjdk-11

  < 10.1.43-r0

• chainguard•tomcat-10.1-openjdk-17

  < 10.1.43-r0

• chainguard•tomcat-10.1-openjdk-21

  < 10.1.43-r0

• chainguard•tomcat-11.0

  < 11.0.9-r0

• chainguard•tomcat-11.0-openjdk-17

  < 11.0.9-r0

• chainguard•tomcat-11.0-openjdk-21

  < 11.0.9-r0

• chainguard•tomcat-11.0-openjdk-25

  < 11.0.9-r0

• chainguard•tomcat-8.5.87

  all

• wolfi•tomcat-11.0

  < 11.0.9-r0

• wolfi•tomcat-11.0-openjdk-17

  < 11.0.9-r0

• wolfi•tomcat-11.0-openjdk-21

  < 11.0.9-r0

• wolfi•tomcat-11.0-openjdk-25

  < 11.0.9-r0

• debian•tomcat10

  < 10.1.52-1~deb12u1 | < 10.1.52-1~deb13u1 | < 10.1.46-1

• debian•tomcat11

  < 11.0.15-1~deb13u1 | < 11.0.11-1

• debian•tomcat9

  < 9.0.107-0+deb11u1 | < 9.0.70-2 | < 9.0.70-2 | < 9.0.70-2

• ubuntu•tomcat10

  all | all | all

• ubuntu•tomcat11

  all | all

• ubuntu•tomcat8

  all

• ubuntu•tomcat9

  all

• org.apache.tomcat•tomcat-coyote

  ≥ 11.0.0-M1, < 11.0.9 | ≥ 10.1.0-M1, < 10.1.43 | ≥ 9.0.0.M1, < 9.0.107 | ≥ 8.5.0, ≤ 8.5.100

• org.apache.tomcat.embed•tomcat-embed-core

  ≥ 8.5.0, ≤ 8.5.100 | ≥ 9.0.0.M1, < 9.0.107 | ≥ 10.1.0-M1, < 10.1.43 | ≥ 11.0.0-M1, < 11.0.9

References (12)

• https://lists.apache.org/thread/p09775q0rd185m6zz98krg0fp45j8kr0
• https://lists.debian.org/debian-lts-announce/2025/07/msg00009.html
• http://www.openwall.com/lists/oss-security/2025/07/10/13
• https://nvd.nist.gov/vuln/detail/CVE-2025-53506
• https://github.com/apache/tomcat/commit/2aa6261276ebe50b99276953591e3a2be7898bdb
• https://github.com/apache/tomcat/commit/434772930f362145516dd60681134e7f0cf8115b
• https://github.com/apache/tomcat/commit/be8f330f83ceddaf3baeed57522e571572b6b99b
• https://github.com/apache/tomcat
• https://ubuntu.com/security/CVE-2025-53506
• https://www.cve.org/CVERecord?id=CVE-2025-53506
• https://security-tracker.debian.org/tracker/CVE-2025-53506
• https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/53xxx/CVE-2025-53506.json