7.5

CVE-2026-66299: apache software foundation apache tomcat Uncontrolled Resource Consumption

CVSS: 7.5v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-66299DEBIAN-CVE-2026-66299
Published 28-07-2026Last modified 28-07-2026
Open JSON

Vulnerability summary

CVE-2026-66299 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in apache software foundation apache tomcat. EPSS estimates a 0.55% chance of exploitation in the next 30 days, higher than 45% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.55%
0%100%
Low · +0.02 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 20 · Related 16
MGASA-2026-0376OPENSUSE-SU-2026:11759-1OPENSUSE-SU-2026:11760-1OPENSUSE-SU-2026:11761-1OPENSUSE-SU-2026:21810-1OPENSUSE-SU-2026:21811-1

Timeline

  1. 28-07-2026
    PublishedVulnerability first disclosed.
  2. 28-07-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.55%

Chance of exploitation in the next 30 days

Percentile

45%

Versus all other CVEs

30-day change

+0.02 pp

From 0.53% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.55%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu6 products
  • tomcat10All versions (No fix recorded)
  • tomcat11All versions (No fix recorded)
  • tomcat6All versions (No fix recorded)
  • tomcat7All versions (No fix recorded)
  • tomcat8All versions (No fix recorded)
Debian3 products
  • tomcat10All versions (No fix recorded) | < 10.1.60-1
  • tomcat11All versions (No fix recorded)
  • tomcat9< 9.0.70-2
Apache1 product
  • tomcat≥ 9.0.89, < 9.0.121 | ≥ 10.1.24, < 10.1.58 | ≥ 11.0.1, < 11.0.25 | 11.0.0:milestone20 | 11.0.0:milestone21 | 11.0.0:milestone22 | 11.0.0:milestone23 | 11.0.0:milestone24 | 11.0.0:milestone25 | 11.0.0:milestone26
Apache software foundation1 product
  • apache tomcat≥ 11.0.0-M20, ≤ 11.0.24 | ≥ 10.1.24, ≤ 10.1.57 | ≥ 9.0.89, ≤ 9.0.120

4 vendors · 11 products

References

5 links