Answer in brief
CVE-2021-41079 records a Unknown severity vulnerability in Apache Tomcat DoS with unexpected TLS packet. The current sources do not mark it as known exploited. The current feed maps Apache Software Foundation/Apache Tomcat (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Apache Software Foundation/Apache Tomcat (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Apache Software Foundation/Apache Tomcatgeneric | Apache Tomcat 8.5 8.5.0 to 8.5.63 || Apache Tomcat 9 9.0.0-M1 to 9.0.43 || Apache Tomcat 10 10.0.0-M1 to 10.0.2 | Not reported |
Published upstream
Sep 16, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 8, 2026
Apache Tomcat 8.5.0 to 8.5.63, 9.0.0-M1 to 9.0.43 and 10.0.0-M1 to 10.0.2 did not properly validate incoming TLS packets. When Tomcat was configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS, a specially crafted packet could be used to trigger an infinite loop resulting in a denial of service.
Quoted source text, attributed separately from HOL analysis.