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.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E Vendor Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E Vendor Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 4.3 · apache, debian, oracleNVD modified 2026-10-08 22:16
Affected (CPE criteria) 131
cpe:2.3:a:apache:tomcat:8.5.0:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.1:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.2:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.3:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.4:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.5:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.6:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.7:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.8:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.9:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.10:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.11:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.12:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.13:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.14:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.15:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.16:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.17:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.18:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.19:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.20:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.21:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.22:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.23:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.24:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.25:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.26:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.27:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.28:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.29:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.30:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.31:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.32:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.33:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.34:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.35:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.36:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.37:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.38:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:8.5.39:*:*:*:*:*:*:*- and 91 more
References 14
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html Broken Link
- https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html Third Party Advisory
- https://security.netapp.com/advisory/ntap-20201016-0007/ Third Party Advisory
- https://www.debian.org/security/2021/dsa-4835 Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html Broken Link
- https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html Third Party Advisory
- https://security.netapp.com/advisory/ntap-20201016-0007/ Third Party Advisory
- https://www.debian.org/security/2021/dsa-4835 Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory