CVE-2020-13943
Description
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.
Official description from the CVE record, published by apache. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
EPSS
- Score
- 0.52639 (52.6% probability)
- Percentile
- 99.0%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA assessment as of Oct 8, 2026
- Automatable
- yes
- Technical impact
- partial
Affected products
Apache Tomcat
- affected: Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37, 8.5.0 to 8.5.57
References
- lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317…
- [debian-lts-announce] 20201014 [SECURITY] [DLA 2407-1] tomcat8 security update (lists.debian.org)mailing-list
- openSUSE-SU-2020:1799 (lists.opensuse.org)vendor-advisory
- openSUSE-SU-2020:1842 (lists.opensuse.org)vendor-advisory
- DSA-4835 (debian.org)vendor-advisory
- oracle.com/security-alerts/cpuApr2021.html
- security.netapp.com/advisory/ntap-20201016-0007
Timeline
- ID reserved
- Record published
- Record last updated
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About CubePath
Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:53 UTC. Sources and licenses