What is the CVSS score of CVE-2025-20209?

CVE-2025-20209 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.3%.

Which versions of Ios Xr are affected by CVE-2025-20209?

Organizations using the Internet Key Exchange face notable risk from CVE-2025-20209 rated CVSS 7.5. Exploitation could compromise the security of affected deployments.

How to fix or mitigate CVE-2025-20209?

Within 7 days: Identify all affected systems running the Internet Key Exchange and apply vendor patches promptly. Monitor vendor channels for patch availability.

Ios Xr CVE-2025-20209

HIGH

Allocation of Resources Without Limits or Throttling (CWE-770)

2025-03-12 psirt@cisco.com

Microsoft Apple Cisco Denial Of Service Ios Xr

7.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 18:31 vuln.today

CVE Published

Mar 12, 2025 - 16:15 nvd

HIGH 7.5

DescriptionCVE.org

This vulnerability is due to improper handling of malformed IKEv2 packets. An attacker could exploit this vulnerability by sending malformed IKEv2 packets to an affected device. A successful exploit could allow the attacker to prevent the affected device from processing any control plane UDP packets, resulting in a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

AnalysisAI

A vulnerability in the Internet Key Exchange version 2 (IKEv2) function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to prevent an affected device from processing any. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as Allocation of Resources Without Limits (CWE-770), which allows attackers to exhaust system resources through uncontrolled allocation. A vulnerability in the Internet Key Exchange version 2 (IKEv2) function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to prevent an affected device from processing any control plane UDP packets.  This vulnerability is due to improper handling of malformed IKEv2 packets. An attacker could exploit this vulnerability by sending malformed IKEv2 packets to an affected device. A successful exploit could allow the attacker to prevent the affected device from processing any control plane UDP packets, resulting in a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Affected products include: Cisco Ios Xr. Version information: version 2.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Set resource limits, implement rate limiting, validate input sizes.