Vulnerability in Linksys Mr9600

CVE-2026-27850

Due to an improperly configured firewall rule, the router will accept any connection on the WAN port with the source port 5222, exposing all services which are normally only accessible through the local network. This issue affects MR9600: 1.0.4.205530; MX4200: 1.0.13.210200.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (34.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-27850: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

References

Frequently asked questions

What is CVE-2026-27850?
CVE-2026-27850 is a high-severity vulnerability in Linksys Mr9600, classified under CWE-940 IMPROPER VERIFICATION OF SOURCE OF A COMMUNICATION CHANNEL. CVSS score: 7.5/10. Published 2026-02-25.
How severe is CVE-2026-27850?
High severity. CVSS v3 base score is 7.5 out of 10.