What is CVE-2021-25265?

CVE-2021-25265 is a high-severity vulnerability in Microsoft Windows. CVSS score: 8.8/10. Published 2021-03-22.

How severe is CVE-2021-25265?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Microsoft Windows

CVE-2021-25265

A malicious website could execute code remotely in Sophos Connect Client before version 2.1.

Published 2021-03-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.018 (78.2th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000

Affected products

Microsoft Windows
Sophos Connect
Sophos Connect Client — versions unspecified

References

community.sophos.com/b/security-blog (Vendor Advisory)
community.sophos.com/b/security-blog/posts/resolved-rce-in-sophos-connect-clien… (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-25265?: CVE-2021-25265 is a high-severity vulnerability in Microsoft Windows. CVSS score: 8.8/10. Published 2021-03-22.
How severe is CVE-2021-25265?: High severity. CVSS v3 base score is 8.8 out of 10.