CVE-2026-77791
published 2026-09-23CVE-2026-77791: Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack. This issue affects Apache…
PriorityP345high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.53%
44.1th percentile
Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack.
This issue affects Apache Tomcat: from 11.0.0-M5 through 11.0.25, from 10.1.8 through 10.1.59, from 9.0.74 through 9.0.121.
The following versions were EOL at the time the CVE was created but are
known to be affected: from 8.5.88 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| apache | tomcat | — | — |
| apache_software_foundation | apache_tomcat | 10.1.8 – 10.1.59 | — |
| apache_software_foundation | apache_tomcat | 11.0.0-M5 – 11.0.25 | — |
| apache_software_foundation | apache_tomcat | 8.5.88 – 8.5.100 | — |
| apache_software_foundation | apache_tomcat | 9.0.74 – 9.0.121 | — |
| debian | tomcat9 | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_redhat7.5HIGH
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GHSA
Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack.
ghsa_unreviewed·2026-09-23
CVE-2026-77791 [HIGH] CWE-400 Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack.
Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack.
This issue affects Apache Tomcat: from 11.0.0-M5 through 11.0.25, from 10.1.8 through 10.1.59, from 9.0.74 through 9.0.121.
The following versions were EOL at the time the CVE was created but are
known to be affected: from 8.5.88 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
Red Hat
tomcat: Apache Tomcat: Denial of Service via busy wait during WebSocket close
vendor_redhat·2026-09-23·CVSS 7.5
CVE-2026-77791 [HIGH] CWE-1050 tomcat: Apache Tomcat: Denial of Service via busy wait during WebSocket close
tomcat: Apache Tomcat: Denial of Service via busy wait during WebSocket close
Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack.
This issue affects Apache Tomcat: from 11.0.0-M5 through 11.0.25, from 10.1.8 through 10.1.59, from 9.0.74 through 9.0.121.
The following versions were EOL at the time the CVE was created but are
known to be affected: from 8.5.88 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
A flaw was found in Apache Tomcat. An uncontrolled resource consumption vulnerability occurs when sending a WebSocket close message, which can lead to a busy wait condition. A remote attacker could exp
No detection rules found.
No public exploits indexed.
Hackernews
⚡ Weekly Recap: NetScaler and FortiMail 0-Days, AI Coding Leaks, Spectre v2 and Ransomware Arrests
blogs_hackernews·2026-10-05·CVSS 7.5
CVE-2026-88779 [HIGH] ⚡ Weekly Recap: NetScaler and FortiMail 0-Days, AI Coding Leaks, Spectre v2 and Ransomware Arrests
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## ⚡ Weekly Recap: NetScaler and FortiMail 0-Days, AI Coding Leaks, Spectre v2 and Ransomware Arrests
A blank field. A public repo. One reply to an email. A box left exposed. None of this sounds dramatic, which is partly the problem. This week’s threats keep finding leverage in small things that were easy to overlook.
There are actively exploited bugs in the mix, cleaner intrusion paths, smarter automation, and a long patch list waiting behind them. Some attacks are getting more capable. Others are still getting in because the basics gave way first.
Here’s what mattered this week.
## ⚡ Threat of the Week
Citrix Warns of Ne
Bugzilla
CVE-2026-73581 CVE-2026-75973 CVE-2026-76183 CVE-2026-77756 CVE-2026-77762 CVE-2026-77791 CVE-2026-78383 CVE-2026-78437 CVE-2026-79677 CVE-2026-86248 CVE-2026-86350 CVE-2026-87022 tomcat: various flaw
bugzilla·2026-09-29·CVSS 9.8
CVE-2026-73581 [CRITICAL] CVE-2026-73581 CVE-2026-75973 CVE-2026-76183 CVE-2026-77756 CVE-2026-77762 CVE-2026-77791 CVE-2026-78383 CVE-2026-78437 CVE-2026-79677 CVE-2026-86248 CVE-2026-86350 CVE-2026-87022 tomcat: various flaw
CVE-2026-73581 CVE-2026-75973 CVE-2026-76183 CVE-2026-77756 CVE-2026-77762 CVE-2026-77791 CVE-2026-78383 CVE-2026-78437 CVE-2026-79677 CVE-2026-86248 CVE-2026-86350 CVE-2026-87022 tomcat: various flaws [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Improper handling of length parameter inconsistency vulnerability in Apache Tomcat allows WebSocket message smuggling when per-message-deflate is used.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121.
The following versions were EOS at the time the CVE was created but are kn
Bugzilla
CVE-2026-77791 tomcat: Apache Tomcat: Denial of Service via busy wait during WebSocket close
bugzilla·2026-09-23·CVSS 7.5
CVE-2026-77791 [HIGH] CVE-2026-77791 tomcat: Apache Tomcat: Denial of Service via busy wait during WebSocket close
CVE-2026-77791 tomcat: Apache Tomcat: Denial of Service via busy wait during WebSocket close
Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack.
This issue affects Apache Tomcat: from 11.0.0-M5 through 11.0.25, from 10.1.8 through 10.1.59, from 9.0.74 through 9.0.121.
The following versions were EOL at the time the CVE was created but are
known to be affected: from 8.5.88 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
2026-09-23
Published