ACTIVELY EXPLOITED

CVE-2020-3118: Cisco IOS XR Software Discovery Protocol Format String Vulnerability

Facts
VendorCisco
ProductIOS XR
Actively exploitedYes
Added to CISA KEV3 Nov 2021
CISA federal deadline3 May 2022
Weakness (CWE)CWE-134

Required action (CISA's text)

Apply updates per vendor instructions.

Description (NVD)

Cisco IOS XR improperly validates string input from certain fields in Cisco Discovery Protocol messages. Exploitation could allow an unauthenticated, adjacent attacker to execute code with administrative privileges or cause a reload on an affected device.

SOURCES

Other Cisco flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.