Description
Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example.
This issue affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through 9.0.120. Users who have followed the security guidance to remove the examples web application are not affected by this issue.
Users are recommended to remove the examples web application or to upgrade to version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache Tomcat | 11.0.0-M20 – ≤ 11.0.24, 10.1.24 – ≤ 10.1.57, 9.0.89 – ≤ 9.0.120 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | tomcat10 | 10.1.60-1 | — |
| Debian 14 | tomcat11 | No fix yet | — |
| Debian 14 | tomcat9 | 9.0.70-2 | — |
| Debian 13 | tomcat10 | 10.1.60-1~deb13u1 | — |
| Debian 13 | tomcat11 | No fix yet | — |
| Debian 13 | tomcat9 | 9.0.70-2 | — |
| Debian 12 | tomcat10 | 10.1.60-1~deb12u1 | — |
| Debian 12 | tomcat9 | 9.0.70-2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | tomcat9 +2 | No fix yet | — |
| Ubuntu 26.04 LTS | tomcat9 +2 | No fix yet | — |
| Ubuntu 24.04 LTS | tomcat9 +1 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | tomcat9 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | tomcat9 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | tomcat8 +1 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | tomcat7 +1 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | tomcat6 +1 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Web Server 7 | jws7-tomcat +9 | 11.0.21-7.redhat_00006.1.el8jws | RHSA-2026:76952 |
| Red Hat JBoss Web Server 6 | jws6-tomcat +9 | 10.1.49-16.redhat_00016.1.el8jws | RHSA-2026:73981 |
| Red Hat Hardened Images 1 | tomcat11 +9 | 11.0.25-0.1.hum1 | RHSA-2026:56039 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLES 15 SP7 | tomcat10 | 10.1.59-150200.5.79.1 | SUSE-SU-2026:4119-1 |
| SLES 15 SP7 | tomcat11 | 11.0.25-150600.13.33.2 | SUSE-SU-2026:4114-1 |
| SLES 15 SP6 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLES 15 SP6 | tomcat10 | 10.1.59-150200.5.79.1 | SUSE-SU-2026:4119-1 |
| SLES 15 SP6 | tomcat11 | 11.0.25-150600.13.33.2 | SUSE-SU-2026:4114-1 |
| SLES 15 SP5 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLES 15 SP5 | tomcat10 | 10.1.59-150200.5.79.1 | SUSE-SU-2026:4119-1 |
| SLES 15 SP4 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLES 12 SP5 | tomcat | 9.0.121-3.177.3 | SUSE-SU-2026:4126-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | tomcat | 9.0.121-160000.1.1 | SUSE-SU-2026:23720-1, SUSE-SU-2026:23700-1 |
| SLES for SAP 16.0 | tomcat10 | 10.1.59-160000.1.1 | SUSE-SU-2026:23711-1, SUSE-SU-2026:23690-1 |
| SLES for SAP 16.0 | tomcat11 | 11.0.25-160000.1.1 | SUSE-SU-2026:23710-1, SUSE-SU-2026:23691-1 |
| SLES for SAP 15 SP6 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLES for SAP 15 SP6 | tomcat10 | 10.1.59-150200.5.79.1 | SUSE-SU-2026:4119-1 |
| SLES for SAP 15 SP6 | tomcat11 | 11.0.25-150600.13.33.2 | SUSE-SU-2026:4114-1 |
| SLES for SAP 15 SP5 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLES for SAP 15 SP5 | tomcat10 | 10.1.59-150200.5.79.1 | SUSE-SU-2026:4119-1 |
| SLES for SAP 15 SP4 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLES 16.0 | tomcat | 9.0.121-160000.1.1 | SUSE-SU-2026:23720-1, SUSE-SU-2026:23700-1 |
| SLES 16.0 | tomcat10 | 10.1.59-160000.1.1 | SUSE-SU-2026:23711-1, SUSE-SU-2026:23690-1 |
| SLES 16.0 | tomcat11 | 11.0.25-160000.1.1 | SUSE-SU-2026:23710-1, SUSE-SU-2026:23691-1 |
| SLE HPC 15 SP5 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
| SLE HPC 15 SP5 | tomcat10 | 10.1.59-150200.5.79.1 | SUSE-SU-2026:4119-1 |
| SLE HPC 15 SP4 | tomcat | 9.0.121-150200.120.1 | SUSE-SU-2026:4203-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | tomcat | 9.0.121-1.1 | openSUSE-SU-2026:11759-1 |
| openSUSE Tumbleweed | tomcat10 | 10.1.59-1.1 | openSUSE-SU-2026:11760-1 |
| openSUSE Tumbleweed | tomcat11 | 11.0.25-1.1 | openSUSE-SU-2026:11761-1 |
| openSUSE Leap 16.0 | tomcat | 9.0.121-160000.1.1 | openSUSE-SU-2026:21823-1 |
| openSUSE Leap 16.0 | tomcat10 | 10.1.59-160000.1.1 | openSUSE-SU-2026:21810-1 |
| openSUSE Leap 16.0 | tomcat11 | 11.0.25-160000.1.1 | openSUSE-SU-2026:21811-1 |
Advisories 22
- WID-SEC-2026-2571 Apache Tomcat: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
- RHSA-2026:76952 Red Hat Security Advisory: Red Hat JBoss Web Server 7.0.2 release and security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:73981 Red Hat Security Advisory: Red Hat JBoss Web Server 6.2.5 release and security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:56039 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- SUSE-SU-2026:23710-1 Security update for tomcat11 SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:23711-1 Security update for tomcat10 SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:23691-1 Security update for tomcat11 SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:23720-1 Security update for tomcat SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:23700-1 Security update for tomcat SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:23690-1 Security update for tomcat10 SUSE / openSUSE Security Updates · Sep 29, 2026
- WID-SEC-2026-3403 Oracle Communications: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 24, 2026
- SUSE-SU-2026:4203-1 Security update for tomcat SUSE / openSUSE Security Updates · Sep 16, 2026
- NCSC-2026-0375 Kwetsbaarheden verholpen in Oracle Communications NCSC-NL (Netherlands) · Sep 16, 2026
- SUSE-SU-2026:4126-1 Security update for tomcat SUSE / openSUSE Security Updates · Sep 15, 2026
- SUSE-SU-2026:4114-1 Security update for tomcat11 SUSE / openSUSE Security Updates · Sep 14, 2026
- SUSE-SU-2026:4119-1 Security update for tomcat10 SUSE / openSUSE Security Updates · Sep 14, 2026
- openSUSE-SU-2026:21823-1 Security update for tomcat SUSE / openSUSE Security Updates · Sep 12, 2026
- openSUSE-SU-2026:11759-1 tomcat-9.0.121-1.1 on GA media SUSE / openSUSE Security Updates · Sep 12, 2026
- openSUSE-SU-2026:11760-1 tomcat10-10.1.59-1.1 on GA media SUSE / openSUSE Security Updates · Sep 12, 2026
- openSUSE-SU-2026:11761-1 tomcat11-11.0.25-1.1 on GA media SUSE / openSUSE Security Updates · Sep 12, 2026
- openSUSE-SU-2026:21811-1 Security update for tomcat11 SUSE / openSUSE Security Updates · Sep 10, 2026
- openSUSE-SU-2026:21810-1 Security update for tomcat10 SUSE / openSUSE Security Updates · Sep 10, 2026
References
- https://lists.apache.org/thread/8owczcc1o8qw1rxmg9gvfk4w2jnh4l5k vendor-advisory