Improper authentication in some Zoom clients before version 5.16.5 may allow an authenticated user to conduct a denial of service via netwo…

published 2023-12-13 2 y ago modified 2026-11-02 6 d ago also EUVD-2023-53588

cvss: 6.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits: 0; none known

Improper authentication in some Zoom clients before version 5.16.5 may allow an authenticated user to conduct a denial of service via network access.

Patch / fix

fixed in 4

zoom meeting_software_development_kit 5.16.5
zoom video_software_development_kit 5.16.5
zoom virtual_desktop_infrastructure 5.14.14, 5.15.12
zoom zoom 5.16.5

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 6 d ago (2026-11-02)

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

Zoom Video Communications, Inc. Zoom Clients

Classification

Weakness

CWE-347 Improper Verification of Cryptographic Signature
CWE-287 Improper Authentication

References

zoom.com /en/trust/security-bulletin/ZSB-23062/
vendor-advisory

Sources

CVE List CVE-2023-49646
NVD CVE-2023-49646

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary