Hazard

Is CVE-2026-20182 being exploited?

Weaponised and widely attempted

Reliable public exploit code exists, or mass exploitation attempts are probable. Patch inside days, not weeks.

Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability

Cisco · Catalyst SD-WAN

CVSS 10 EPSS 90% no public exploit indexed Fix deadline passed 17 May 2026

What it is

Cisco Catalyst SD-WAN Controller & Manager contain an authentication bypass vulnerability that allows an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system.

Why we say that

  • EPSS puts exploitation in the next 30 days at 90%
  • CISA's federal remediation deadline (2026-05-17) has passed
  • CVSS 10 critical
  • Listed in the CISA Known Exploited Vulnerabilities catalogue

Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.

What to do

Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlined in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

What it costs when this goes wrong

This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:

All UK cases caused by unpatched software →