CVE catalog
CVE-2020-11996
A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient n
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 26.70% · Oct 27, 2026
A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive.
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 |
| Ubuntu | tomcat8 | pro | 8.5.21-1ubuntu1 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.29-1 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.30-1 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.30-1ubuntu1 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.30-1ubuntu1.2 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.30-1ubuntu1.3 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.30-1ubuntu1.4 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.1 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.2 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.3 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.3+esm1 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.3+esm2 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.3+esm3 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.3+esm4 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.3+esm5 | vulnerable |
| Ubuntu | tomcat8 | pro | 8.5.39-1ubuntu1~18.04.3+esm6 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3~18.04.1 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.1 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm1 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm2 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm3 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm4 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm5 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm6 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm7 | vulnerable |
| Ubuntu | tomcat9 | pro | 9.0.16-3ubuntu0.18.04.2+esm8 | vulnerable |
| Ubuntu | tomcat9 | 20.04 | 9.0.24-1 | vulnerable |
| Ubuntu | tomcat9 | 20.04 | 9.0.27-1 | vulnerable |
| Ubuntu | tomcat9 | 20.04 | 9.0.31-1 | vulnerable |
| Ubuntu | tomcat9 | 20.04 | 9.0.31-1ubuntu0.1 | fixed |
| Ubuntu | tomcat9 | 20.04 | 9.0.24-1 | vulnerable |
| Ubuntu | tomcat9 | 20.04 | 9.0.27-1 | vulnerable |
| Ubuntu | tomcat9 | 20.04 | 9.0.31-1 | vulnerable |
| Ubuntu | tomcat9 | 20.04 | 9.0.31-1ubuntu0.1 | fixed |
| Suse | tomcat | linux enterprise high performance computing 15-espos | 9.0.36-3.60.1 | fixed |
| Suse | tomcat | linux enterprise high performance computing 15-ltss | 9.0.36-3.60.1 | fixed |
| Suse | tomcat | linux enterprise server 15-ltss | 9.0.36-3.60.1 | fixed |
| Suse | tomcat | linux enterprise server for sap applications 15 | 9.0.36-3.60.1 | fixed |
| Suse | tomcat | openstack cloud 9 | 9.0.36-3.42.2 | fixed |
| Suse | tomcat | openstack cloud crowbar 9 | 9.0.36-3.42.2 | fixed |
| Suse | tomcat | linux enterprise server for sap applications 12 sp4 | 9.0.36-3.42.2 | fixed |
| Suse | tomcat | linux enterprise server 12 sp4-ltss | 9.0.36-3.42.2 | fixed |
| Suse | tomcat | linux enterprise server 12 sp5 | 9.0.36-3.42.2 | fixed |
| Suse | tomcat | linux enterprise server for sap applications 12 sp5 | 9.0.36-3.42.2 | fixed |
| Suse | tomcat | linux enterprise module for web and scripting 15 sp2 | 9.0.36-3.3.1 | fixed |
| Opensuse | tomcat | leap 15.2 | 9.0.36-lp152.2.3.1 | fixed |
| Suse | tomcat | linux enterprise module for web and scripting 15 sp1 | 9.0.36-4.38.1 | fixed |
| Opensuse | tomcat | leap 15.1 | 9.0.36-lp151.3.24.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | tomcat9 | source | sid | 9.0.36-1 | not yet assigned | Not reported | Not reported |
| Debian | tomcat9 | source | forky | 9.0.36-1 | not yet assigned | Not reported | Not reported |
| Debian | tomcat9 | source | trixie | 9.0.36-1 | not yet assigned | Not reported | Not reported |
| Debian | tomcat9 | source | bookworm | 9.0.36-1 | not yet assigned | Not reported | Not reported |
| Ubuntu | tomcat9 | deb | 20.04 | 9.0.31-1ubuntu0.1 | Not reported | UBUNTU-CVE-2020-11996 | Not reported |
| Ubuntu | tomcat9 | deb | 20.04 | 9.0.31-1ubuntu0.1 | Not reported | USN-4596-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise high performance computing 15-espos | 9.0.36-3.60.1 | Not reported | SUSE-SU-2020:1841-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise high performance computing 15-ltss | 9.0.36-3.60.1 | Not reported | SUSE-SU-2020:1841-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server 15-ltss | 9.0.36-3.60.1 | Not reported | SUSE-SU-2020:1841-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server for sap applications 15 | 9.0.36-3.60.1 | Not reported | SUSE-SU-2020:1841-1 | Not reported |
| Suse | tomcat | rpm | openstack cloud 9 | 9.0.36-3.42.2 | Not reported | SUSE-SU-2020:1963-1 | Not reported |
| Suse | tomcat | rpm | openstack cloud crowbar 9 | 9.0.36-3.42.2 | Not reported | SUSE-SU-2020:1963-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server for sap applications 12 sp4 | 9.0.36-3.42.2 | Not reported | SUSE-SU-2020:1963-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server 12 sp4-ltss | 9.0.36-3.42.2 | Not reported | SUSE-SU-2020:1963-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server 12 sp5 | 9.0.36-3.42.2 | Not reported | SUSE-SU-2020:1963-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise server for sap applications 12 sp5 | 9.0.36-3.42.2 | Not reported | SUSE-SU-2020:1963-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise module for web and scripting 15 sp2 | 9.0.36-3.3.1 | Not reported | SUSE-SU-2020:1983-1 | Not reported |
| Opensuse | tomcat | rpm | leap 15.2 | 9.0.36-lp152.2.3.1 | Not reported | OPENSUSE-SU-2020:1063-1 | Not reported |
| Suse | tomcat | rpm | linux enterprise module for web and scripting 15 sp1 | 9.0.36-4.38.1 | Not reported | SUSE-SU-2020:1962-1 | Not reported |
| Opensuse | tomcat | rpm | leap 15.1 | 9.0.36-lp151.3.24.1 | Not reported | OPENSUSE-SU-2020:1051-1 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libtomcat9-java]Fixed
Source package: [tomcat9]
Details (2)
9.0.70-2· all · bookwormFixed · Fixed:
9.0.36-1nvd · tomcat9 · debian · bookworm; nvd · tomcat9 · debian · 12
9.0.70-2· all · bookwormFixed · Fixed:
9.0.36-1nvd · 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:
9.0.36-1nvd · tomcat9 · debian · 13
9.0.95-1· all · trixieFixed · Fixed:
9.0.36-1nvd · tomcat9 · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2020_1841-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2020-11996]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2020-11996]
- [https://osv.dev/vulnerability/DLA-2279-1]
- [https://osv.dev/vulnerability/DSA-4727-1]
- [https://osv.dev/vulnerability/SUSE-SU-2020:1841-1]
- [https://osv.dev/vulnerability/SUSE-SU-2020:1962-1]
- [https://osv.dev/vulnerability/SUSE-SU-2020:1963-1]
- [https://osv.dev/vulnerability/SUSE-SU-2020:1983-1]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2020-11996]
- [https://osv.dev/vulnerability/USN-4596-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2020:1051-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2020:1063-1]
- [https://security-tracker.debian.org/tracker/CVE-2020-11996]
- [https://security.access.redhat.com/data/csaf/v2/vex/2020/cve-2020-11996.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2024/wid-sec-w-2024-0528.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]