CVE-2020-13943
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 nu
CVSS
4.3
Medium
EPSS
55.0%
p99
KEV
—
Exploit Today
30
0-100
Published: Oct 12, 2020 · Last modified: Oct 8, 2026
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.
- lists.opensuse.orghttp://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html
- lists.opensuse.orghttp://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html
- lists.apache.orghttps://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E
- lists.debian.orghttps://lists.debian.org/debian-lts-announce/2020/10/msg00019.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20201016-0007/
- www.debian.orghttps://www.debian.org/security/2021/dsa-4835
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuApr2021.html
- lists.opensuse.orghttp://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html
- lists.opensuse.orghttp://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html
- lists.apache.orghttps://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E
- lists.debian.orghttps://lists.debian.org/debian-lts-announce/2020/10/msg00019.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20201016-0007/
- www.debian.orghttps://www.debian.org/security/2021/dsa-4835
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuApr2021.html
No related CVEs by CWE or product.