CVE-2026-66299

EUVD-2026-49855

28.07.2026, 15:17

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.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	5.3 MEDIUM	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Base Score

CVSS 3.x

EPSS Score

Percentile: 43.33%

Affected Products (NVD)

Vendor	Product	Version
apache	tomcat	9.0.89 ≤ 𝑥 < 9.0.121
apache	tomcat	10.1.24 ≤ 𝑥 < 10.1.58
apache	tomcat	11.0.1 ≤ 𝑥 < 11.0.25
apache	tomcat	11.0.0:milestone20
apache	tomcat	11.0.0:milestone21
apache	tomcat	11.0.0:milestone22
apache	tomcat	11.0.0:milestone23
apache	tomcat	11.0.0:milestone24
apache	tomcat	11.0.0:milestone25
apache	tomcat	11.0.0:milestone26

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

tomcat10

bookworm	unimportant
bookworm (security)	unimportant
forky	unimportant
sid	unimportant
trixie	unimportant
trixie (security)	unimportant

tomcat11

forky	unimportant
sid	unimportant
trixie	unimportant
trixie (security)	unimportant

tomcat9

bookworm	9.0.70-2 fixed
forky	9.0.118-1 fixed
sid	9.0.118-1 fixed
trixie	9.0.95-1 fixed

Ubuntu Releases

Ubuntu Product

Codename

tomcat6

jammy	dne
noble	dne
resolute	dne
trusty	needs-triage
xenial	not-affected

tomcat7

bionic	not-affected
jammy	dne
noble	dne
resolute	dne
trusty	needs-triage
xenial	needs-triage

tomcat8

bionic	needs-triage
jammy	dne
noble	dne
resolute	dne
xenial	needs-triage

tomcat9

bionic	needs-triage
focal	needs-triage
jammy	needs-triage
noble	needs-triage
resolute	needs-triage

tomcat10

jammy	dne
noble	needs-triage
resolute	needs-triage

tomcat11

jammy	dne
noble	dne
resolute	needs-triage

openSUSE / SLES Releases

openSUSE Product

Release

tomcat10

suse enterprise sap 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP7	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP7	10.1.59-150200.5.79.1 fixed

tomcat10-admin-webapps

suse enterprise sap 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP7	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP7	10.1.59-150200.5.79.1 fixed

tomcat10-el-5_0-api

suse enterprise sap 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP7	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP7	10.1.59-150200.5.79.1 fixed

tomcat10-jsp-3_1-api

suse enterprise sap 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP7	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP7	10.1.59-150200.5.79.1 fixed

tomcat10-lib

suse enterprise sap 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP7	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP7	10.1.59-150200.5.79.1 fixed

tomcat10-servlet-6_0-api

suse enterprise sap 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP7	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP7	10.1.59-150200.5.79.1 fixed

tomcat10-webapps

suse enterprise sap 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise sap 15 SP7	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP5	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP6	10.1.59-150200.5.79.1 fixed
suse enterprise server 15 SP7	10.1.59-150200.5.79.1 fixed

tomcat11

suse enterprise sap 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise sap 15 SP7	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP7	11.0.25-150600.13.33.2 fixed

tomcat11-admin-webapps

suse enterprise sap 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise sap 15 SP7	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP7	11.0.25-150600.13.33.2 fixed

tomcat11-el-6_0-api

suse enterprise sap 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise sap 15 SP7	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP7	11.0.25-150600.13.33.2 fixed

tomcat11-jsp-4_0-api

suse enterprise sap 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise sap 15 SP7	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP7	11.0.25-150600.13.33.2 fixed

tomcat11-lib

suse enterprise sap 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise sap 15 SP7	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP7	11.0.25-150600.13.33.2 fixed

tomcat11-servlet-6_1-api

suse enterprise sap 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise sap 15 SP7	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP7	11.0.25-150600.13.33.2 fixed

tomcat11-webapps

suse enterprise sap 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise sap 15 SP7	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP6	11.0.25-150600.13.33.2 fixed
suse enterprise server 15 SP7	11.0.25-150600.13.33.2 fixed

Common Weakness Enumeration

CWE-400 - Uncontrolled Resource Consumption
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

References

https://lists.apache.org/thread/8owczcc1o8qw1rxmg9gvfk4w2jnh4l5k

http://www.openwall.com/lists/oss-security/2026/07/28/25