Exposure of Sensitive Information to an Unauthorized Actor in Apache Tomcat
If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible that a subsequent request made on that connection could contain HTTP headers - including HTTP/2 pseudo headers - from a previous request rather than the intended headers. This could lead to users seeing responses for unexpected resources.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.apache.tomcat:tomcat-coyote | >= 10.0.0-M1, < 10.0.0-M8, >= 9.0.0-M1, < 9.0.38, >= 8.5.0, < 8.5.58 | 10.0.0-M8, 9.0.38, 8.5.58 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2020-13943
- https://github.com/apache/tomcat/commit/1bbc650cbc3f08d85a1ec6d803c47ae53a84f3bb
- https://github.com/apache/tomcat/commit/55911430df13f8c9998fbdee1f9716994d2db59b
- https://github.com/apache/tomcat/commit/9d7def063b47407a09a2f9202beed99f4dcb292a
- https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html
- https://security.netapp.com/advisory/ntap-20201016-0007
- https://www.debian.org/security/2021/dsa-4835
- https://www.oracle.com/security-alerts/cpuApr2021.html
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N- Weakness (CWE)
CWE-200- Platform
- Java / Kotlin (Maven)
- Package
org.apache.tomcat:tomcat-coyote- Disclosed
- 09.02.2022
- Updated
- 11.10.2026 11:21
Sources and licenses
OSV / GitHub Advisory Database - GHSA-f268-65qc-98vg - CC BY 4.0
Vulnerability history: org.apache.tomcat:tomcat-coyote
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 33
- First → latest
- 06.2020 05.2026
- Without a fix
- 0
- Exploited in attacks
- 1
Severity breakdown
- Critical 2
- High 17
- Medium 13
- Low 1
Disclosures per year
- 2020: 1
- 2021: 1
- 2022: 8
- 2023: 7
- 2024: 5
- 2025: 4
- 2026: 7
-
Exposure of Sensitive Information to an Unauthorized Actor in Apache Tomcat this entry
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