CVE-2025-20209 | Cisco IOS XR Software Internet Key Exchange Version 2 Denial of Service Vulnerability

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.

Published: 2025-03-12 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-20209 is rated Moderate Risk (43.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.51%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-20209

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.56% 0.51% -0.06%
2 2026-04-25 0.74% 0.56% -0.17%
3 2026-04-22 — 0.74% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-20209

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-20209

Affected software / configurations for CVE-2025-20209

Vendor Product Version Raw CPE
cisco ios_xr 6.5.1 cpe:2.3:o:cisco:ios_xr:6.5.1:*:*:*:*:*:*:*
cisco ios_xr 6.5.2 cpe:2.3:o:cisco:ios_xr:6.5.2:*:*:*:*:*:*:*
cisco ios_xr 6.5.3 cpe:2.3:o:cisco:ios_xr:6.5.3:*:*:*:*:*:*:*
cisco ios_xr 6.6.1 cpe:2.3:o:cisco:ios_xr:6.6.1:*:*:*:*:*:*:*
cisco ios_xr 6.6.2 cpe:2.3:o:cisco:ios_xr:6.6.2:*:*:*:*:*:*:*
cisco ios_xr 6.6.3 cpe:2.3:o:cisco:ios_xr:6.6.3:*:*:*:*:*:*:*
cisco ios_xr 6.6.25 cpe:2.3:o:cisco:ios_xr:6.6.25:*:*:*:*:*:*:*
cisco ios_xr 7.0.0 cpe:2.3:o:cisco:ios_xr:7.0.0:*:*:*:*:*:*:*
cisco ios_xr 7.0.1 cpe:2.3:o:cisco:ios_xr:7.0.1:*:*:*:*:*:*:*
cisco ios_xr 7.0.2 cpe:2.3:o:cisco:ios_xr:7.0.2:*:*:*:*:*:*:*
cisco ios_xr 7.1.1 cpe:2.3:o:cisco:ios_xr:7.1.1:*:*:*:*:*:*:*
cisco ios_xr 7.1.2 cpe:2.3:o:cisco:ios_xr:7.1.2:*:*:*:*:*:*:*
cisco ios_xr 7.2.0 cpe:2.3:o:cisco:ios_xr:7.2.0:*:*:*:*:*:*:*
cisco ios_xr 7.2.1 cpe:2.3:o:cisco:ios_xr:7.2.1:*:*:*:*:*:*:*
cisco ios_xr 7.2.2 cpe:2.3:o:cisco:ios_xr:7.2.2:*:*:*:*:*:*:*
cisco ios_xr 7.3.1 cpe:2.3:o:cisco:ios_xr:7.3.1:*:*:*:*:*:*:*
cisco ios_xr 7.3.2 cpe:2.3:o:cisco:ios_xr:7.3.2:*:*:*:*:*:*:*
cisco ios_xr 7.3.27 cpe:2.3:o:cisco:ios_xr:7.3.27:*:*:*:*:*:*:*
cisco ios_xr 7.4.1 cpe:2.3:o:cisco:ios_xr:7.4.1:*:*:*:*:*:*:*
cisco ios_xr 7.4.2 cpe:2.3:o:cisco:ios_xr:7.4.2:*:*:*:*:*:*:*
cisco ios_xr 7.5.1 cpe:2.3:o:cisco:ios_xr:7.5.1:*:*:*:*:*:*:*
cisco ios_xr 7.5.2 cpe:2.3:o:cisco:ios_xr:7.5.2:*:*:*:*:*:*:*
cisco ios_xr 7.6.1 cpe:2.3:o:cisco:ios_xr:7.6.1:*:*:*:*:*:*:*
cisco ios_xr 7.6.2 cpe:2.3:o:cisco:ios_xr:7.6.2:*:*:*:*:*:*:*
cisco ios_xr 7.7.1 cpe:2.3:o:cisco:ios_xr:7.7.1:*:*:*:*:*:*:*
cisco ios_xr 7.7.2 cpe:2.3:o:cisco:ios_xr:7.7.2:*:*:*:*:*:*:*
cisco ios_xr 7.7.21 cpe:2.3:o:cisco:ios_xr:7.7.21:*:*:*:*:*:*:*
cisco ios_xr 7.8.1 cpe:2.3:o:cisco:ios_xr:7.8.1:*:*:*:*:*:*:*
cisco ios_xr 7.8.2 cpe:2.3:o:cisco:ios_xr:7.8.2:*:*:*:*:*:*:*
cisco ios_xr 7.8.22 cpe:2.3:o:cisco:ios_xr:7.8.22:*:*:*:*:*:*:*
cisco ios_xr 7.9.1 cpe:2.3:o:cisco:ios_xr:7.9.1:*:*:*:*:*:*:*
cisco ios_xr 7.9.2 cpe:2.3:o:cisco:ios_xr:7.9.2:*:*:*:*:*:*:*
cisco ios_xr 7.10.1 cpe:2.3:o:cisco:ios_xr:7.10.1:*:*:*:*:*:*:*
cisco ios_xr 7.10.2 cpe:2.3:o:cisco:ios_xr:7.10.2:*:*:*:*:*:*:*
cisco ios_xr 7.11.1 cpe:2.3:o:cisco:ios_xr:7.11.1:*:*:*:*:*:*:*
cisco ios_xr 7.11.2 cpe:2.3:o:cisco:ios_xr:7.11.2:*:*:*:*:*:*:*
cisco ios_xr 24.1.1 cpe:2.3:o:cisco:ios_xr:24.1.1:*:*:*:*:*:*:*
cisco ios_xr 24.1.2 cpe:2.3:o:cisco:ios_xr:24.1.2:*:*:*:*:*:*:*
cisco ios_xr 24.2.1 cpe:2.3:o:cisco:ios_xr:24.2.1:*:*:*:*:*:*:*
cisco ios_xr 24.2.11 cpe:2.3:o:cisco:ios_xr:24.2.11:*:*:*:*:*:*:*

References for CVE-2025-20209

cvelogic Threat Intelligence