What is CVE-2021-26718?

CVE-2021-26718 is a medium-severity vulnerability in Kaspersky Internet Security, classified under Incorrect Authorization. CVSS score: 5.5/10. Published 2021-04-01.

How severe is CVE-2021-26718?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Auth bypass in Kaspersky Internet Security

CVE-2021-26718

KIS for macOS in some use cases was vulnerable to AV bypass that potentially allowed an attacker to disable anti-virus protection.

Vulnerability class: Broken Access Control

Published 2021-04-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Kaspersky Internet Security
Kaspersky Internet Security For Mac — versions prior to 21.1

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

support.kaspersky.com/general/vulnerability.aspx (Broken Link, Vendor Advisory)

Frequently asked questions

What is CVE-2021-26718?: CVE-2021-26718 is a medium-severity vulnerability in Kaspersky Internet Security, classified under Incorrect Authorization. CVSS score: 5.5/10. Published 2021-04-01.
How severe is CVE-2021-26718?: Medium severity. CVSS v3 base score is 5.5 out of 10.