Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities (CVE-2020-3569) | HOL Guard CVE

High severityKnown ExploitedCVE-2020-3569

Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities

Answer in brief

CVE-2020-3569 records a High severity vulnerability in Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities. The current sources mark it as known exploited. The current feed maps Cisco/Cisco IOS XR Software (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 23, 2020Updated Oct 21, 2025Source checked Sep 17, 2026First seen by HOL May 24, 2026Material review Oct 21, 2025

Upstream Advisory

Key facts

Risk: High
Exploitation: Known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Cisco/Cisco IOS XR Software (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Cisco/Cisco IOS XR Softwaregeneric	n/a	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Cisco/Cisco IOS XR Software.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 23, 2020
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 21, 2025
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
May 24, 2026
Added to CISA KEV
Nov 3, 2021
Evidence: source:kev:kev:kev:record

Sources and claim methodology

Upstream source description

Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to either immediately crash the Internet Group Management Protocol (IGMP) process or make it consume available memory and eventually crash. The memory consumption may negatively impact other processes that are running on the device. These vulnerabilities are due to the incorrect handling of IGMP packets. An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to immediately crash the IGMP process or cause memory exhaustion, resulting in other processes becoming unstable. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address these vulnerabilities.

Quoted source text, attributed separately from HOL analysis.