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CVE-2021-31755 in Tenda AC11 Router: known exploited

Generated from its entry in CISA's catalogue of known exploited vulnerabilities as of 3 November 2026.

Attackers are exploiting CVE-2021-31755 in Tenda AC11 Router. CISA has listed it as known exploited since 3 November 2021.

ProductTenda AC11 Router
Known exploited since3 November 2021
Ransomware useNot recorded
EU vulnerability databaseEUVD-2021-18639
SourcesNVD · CISA KEV

What it means

Attackers have used this vulnerability in real attacks. An unpatched Tenda AC11 Router that can be reached from the internet is exposed to them.

What to do

  1. Apply the vendor's fix to every system running Tenda AC11 Router, starting with those reachable from the internet. Take a system off the internet until it can be fixed.
  2. Check the system for signs that it was reached before the fix.

How Vardion finds it

Wherever a scan or your imported scanner results find CVE-2021-31755, Vardion names the systems affected and puts the fix at the top of the list.

Know before an attacker does

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