CVE-2020-13935

High

High exploit probability or critical severity with a known exploit.

CVSS base

7.5 HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — probability of exploitation (30 days)

86.6%

99.7th percentile

CISA KEV

Not listed

Weakness / dates

CWE-835

Published 2020-07-14 · modified 2026-08-25

CVSS breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector	N	Network
Attack Complexity	L	Low
Privileges Required	N	None
User Interaction	N	None
Scope	U	Unchanged
Confidentiality	N	None
Integrity	N	None
Availability	H	High

Timeline

2020-07-14 — Published (NVD)
2026-08-25 — Last modified (NVD)

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.

Affected

apache canonical debian mcafee netapp opensuse oracle

References

Official: NVD · CVE.org