CVE catalog
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 number of concurrent streams for a connection (in violation of
- Severity
- Medium · CVSS 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 54.97% · Oct 25, 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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | tomcat9 | sid | 9.0.122-1 | fixed |
| Debian | tomcat9 | forky | 9.0.122-1 | fixed |
| Debian | tomcat9 | trixie | 9.0.95-1 | fixed |
| Debian | tomcat9 | bookworm | 9.0.70-2 | fixed |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Cpe | tomcat | Not reported | Not reported | unknown |
| Opensuse | tomcat | leap 15.1 | 9.0.36-lp151.3.33.1 | fixed |
| Opensuse | tomcat | leap 15.2 | 9.0.36-lp152.2.10.1 | fixed |
| Suse | tomcat | linux enterprise module for web and scripting 15 sp2 | 9.0.36-3.12.3 | fixed |
| Suse | tomcat | linux enterprise module for web and scripting 15 sp1 | 9.0.36-4.47.3 | fixed |
| Suse | tomcat | linux enterprise high performance computing 15-espos | 9.0.36-3.74.1 | fixed |
| Suse | tomcat | linux enterprise high performance computing 15-ltss | 9.0.36-3.74.1 | fixed |
| Suse | tomcat | linux enterprise server 15-ltss | 9.0.36-3.74.1 | fixed |
| Suse | tomcat | linux enterprise server for sap applications 15 | 9.0.36-3.74.1 | fixed |
| Suse | tomcat | linux enterprise server 12 sp5 | 9.0.36-3.50.1 | fixed |
| Suse | tomcat | linux enterprise server for sap applications 12 sp5 | 9.0.36-3.50.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | tomcat9 | source | sid | 9.0.38-1 | not yet assigned | Not reported | Not reported |
| Debian | tomcat9 | source | forky | 9.0.38-1 | not yet assigned | Not reported | Not reported |
| Debian | tomcat9 | source | trixie | 9.0.38-1 | not yet assigned | Not reported | Not reported |
| Debian | tomcat9 | source | bookworm | 9.0.38-1 | not yet assigned | Not reported | Not reported |
| Opensuse | tomcat | rpm | leap 15.1 | 9.0.36-lp151.3.33.1 | Not reported | OPENSUSE-SU-2020:1842-1 | Not reported |
| Opensuse | tomcat | rpm | leap 15.2 | 9.0.36-lp152.2.10.1 | Not reported | OPENSUSE-SU-2020:1799-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise module for web and scripting 15 sp2 | 9.0.36-3.12.3 | Not reported | SUSE-SU-2020:3068-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise module for web and scripting 15 sp1 | 9.0.36-4.47.3 | Not reported | SUSE-SU-2020:3069-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise high performance computing 15-espos | 9.0.36-3.74.1 | Not reported | SUSE-SU-2021:0040-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise high performance computing 15-ltss | 9.0.36-3.74.1 | Not reported | SUSE-SU-2021:0040-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server 15-ltss | 9.0.36-3.74.1 | Not reported | SUSE-SU-2021:0040-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server for sap applications 15 | 9.0.36-3.74.1 | Not reported | SUSE-SU-2021:0040-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server 12 sp5 | 9.0.36-3.50.1 | Not reported | SUSE-SU-2020:2996-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server for sap applications 12 sp5 | 9.0.36-3.50.1 | Not reported | SUSE-SU-2020:2996-1 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libtomcat9-java]Fixed
Source package: [tomcat9]
Details (2)
9.0.70-2· all · bookwormFixed · Fixed:
9.0.38-1nvd · tomcat9 · debian · bookworm; nvd · tomcat9 · debian · 12
9.0.70-2· all · bookwormFixed · Fixed:
9.0.38-1nvd · tomcat9 · debian · bookworm; nvd · tomcat9 · debian · 12
[Debian 13 (Trixie)]
- [libtomcat9-java]Fixed
Source package: [tomcat9]
Details (2)
9.0.95-1· all · trixieFixed · Fixed:
9.0.38-1nvd · tomcat9 · debian · 13
9.0.95-1· all · trixieFixed · Fixed:
9.0.38-1nvd · tomcat9 · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2020_2996-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2020-13943]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2020-13943]
- [https://osv.dev/vulnerability/DLA-2407-1]
- [https://osv.dev/vulnerability/DSA-4835-1]
- [https://osv.dev/vulnerability/SUSE-SU-2020:2996-1]
- [https://osv.dev/vulnerability/SUSE-SU-2020:3068-1]
- [https://osv.dev/vulnerability/SUSE-SU-2020:3069-1]
- [https://osv.dev/vulnerability/SUSE-SU-2021:0040-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2020:1799-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2020:1842-1]
- [https://security-tracker.debian.org/tracker/CVE-2020-13943]
- [https://security.access.redhat.com/data/csaf/v2/vex/2020/cve-2020-13943.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2020/wid-sec-w-2023-2467.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]