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-2020-13935

CVE-2020-13935HIGH

n/a Apache Tomcat — The payload length in a WebSocket frame was not correctly validated in Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .8661   99.7     —

AFFECTED
  Product        Versions                                                                                        Fixed
  Apache Tomcat  Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to 8.5.56, 7.0.27 to 7.0.104 –  —

TIMELINE
  Jun 8   Reserved by apache
  Jul 14  Published (CNA: apache)
  Oct 8   ENRICHED — CVE-2020-13935 (Apache Tomcat). Received CVSS 7.5 and CPE data from NVD.

CWE-835 · CNA: apache · CVSS v3.1 · 17 references · NVD status: Modified

Description

The payload length in a WebSocket frame was not correctly validated in Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to 8.5.56 and 7.0.27 to 7.0.104. Invalid payload lengths could trigger an infinite loop. Multiple requests with invalid payload lengths could lead to a denial of service.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
June 8, 2020	Reserved	Reserved by apache
July 14, 2020	Published	Published (CNA: apache)
October 8, 2026	ENRICHED	ENRICHED — CVE-2020-13935 (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
n/a	Apache Tomcat	—	Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to 8.5.56, 7.0.27 to 7.0.104	—

Weaknesses

CWE-835

References (17)

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00084.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00088.html [Mailing List, Third Party Advisory]
https://kc.mcafee.com/corporate/index?page=content&id=SB10332 [Third Party Advisory]
https://lists.apache.org/thread.html/r4e5d3c09f4dd2923191e972408b40fb8b42dbff0bc7904d44b651e50%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rd48c72bd3255bda87564d4da3791517c074d94f8a701f93b85752651%40%3Cannounce.tomcat.apache.org%3E [Mailing List, Release Notes, Vendor Advisory]
https://lists.debian.org/debian-lts-announce/2020/07/msg00017.html [Mailing List, Third Party Advisory]
https://security.netapp.com/advisory/ntap-20200724-0003/ [Third Party Advisory]
https://usn.ubuntu.com/4448-1/ [Third Party Advisory]
https://usn.ubuntu.com/4596-1/ [Third Party Advisory]
https://www.debian.org/security/2020/dsa-4727 [Third Party Advisory]
https://www.oracle.com//security-alerts/cpujul2021.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuApr2021.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuapr2022.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpujan2021.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpujan2022.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuoct2020.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuoct2021.html [Not Applicable, Third Party Advisory]

Authoritative record: CVE-2020-13935 at cve.org

Weaknesses: CWE-835

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-13935 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.