Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-41079

CVE-2021-41079HIGH

Apache Tomcat DoS with unexpected TLS packet

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0718   94.2     —

AFFECTED
  Product        Versions                             Fixed
  Apache Tomcat  Apache Tomcat 8.5 8.5.0 to 8.5.63 –  —

TIMELINE
  Sep 15  Reserved by apache
  Sep 16  Published (CNA: apache)
  Oct 8   ENRICHED — CVE-2021-41079 (Apache Software Foundation Apache Tomcat). Received CVSS 7.5 and CPE data from NVD.

CWE-835, CWE-20 · CNA: apache · CVSS v3.1 · 6 references · NVD status: Modified

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 15, 2021	Reserved	Reserved by apache
September 16, 2021	Published	Published (CNA: apache)
October 8, 2026	ENRICHED	ENRICHED — CVE-2021-41079 (Apache Software Foundation Apache Tomcat). Received CVSS 7.5 and CPE data from NVD.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Apache Software Foundation	Apache Tomcat	—	Apache Tomcat 8.5 8.5.0 to 8.5.63	—

Weaknesses

CWE-835 · CWE-20

References (6)

https://lists.apache.org/thread.html/r6b6b674e3f168dd010e67dbe6848b866e2acf26371452fdae313b98a%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rb4de81ac647043541a32881099aa6eb5a23f1b7fd116f713f8ab9dbe%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rccdef0349fdf4fb73a4e4403095446d7fe6264e0a58e2df5c6799434%40%3Cannounce.tomcat.apache.org%3E [Mailing List, Vendor Advisory]
https://lists.debian.org/debian-lts-announce/2021/09/msg00012.html [Mailing List, Third Party Advisory]
https://security.netapp.com/advisory/ntap-20211008-0005/ [Third Party Advisory]
https://www.debian.org/security/2021/dsa-4986 [Third Party Advisory]

Authoritative record: CVE-2021-41079 at cve.org

Vendors: apache

Weaknesses: CWE-835 · CWE-20

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-41079 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.