TI-2025-14635 Aliases CVE-2025-20340 GHSA-7xc2-hq29-896q

Cisco IOS XR Address Resolution Protocol Broadcast Storm Vulnerability

LOW 33CWE-400Published 2025-09-10 · Updated 2025-09-10

Key facts

Attack vector: Adjacent network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.

Summary

A vulnerability in the Address Resolution Protocol (ARP) implementation of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to trigger a broadcast storm, leading to a denial of service (DoS) condition on an affected device.  This vulnerability is due to how Cisco IOS XR Software processes a high, sustained rate of ARP traffic hitting the management interface. Under certain conditions, an attacker could exploit this vulnerability by sending an excessive amount of traffic to the management interface of an affected device, overwhelming its ARP processing capabilities. A successful exploit could result in degraded device performance, loss of management connectivity, and complete unresponsiveness of the system, leading to a DoS condition.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00641 50th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cisco	Cisco IOS XR Software	6.5.3; 6.5.29; 6.5.1; 6.6.1; 6.5.2; 6.5.92; 6.5.15; 6.6.2; 7.0.1; 6.6.25; 6.5.26; 6.6.11; 6.5.25; 6.5.28; 6.5.93; 6.6.12; 6.5.90; 7.0.0; 7.1.1; 7.0.90; 6.6.3; 6.7.1; 7.0.2; 7.1.15; 7.2.0; 7.2.1; 7.1.2; 6.7.2; 7.0.11; 7.0.12; 7.0.14; 7.1.25; 6.6.4; 7.2.12; 7.3.1; 7.1.3; 6.7.3; 7.4.1; 7.2.2; 6.7.4; 6.5.31; 7.3.15; 7.3.16; 6.8.1; 7.4.15; 6.5.32; 7.3.2; 7.5.1; 7.4.16; 7.3.27; 7.6.1; 7.5.2; 7.8.1; 7.6.15; 7.5.12; 7.8.12; 7.3.3; 7.7.1; 6.8.2; 7.3.4; 7.4.2; 6.7.35; 6.9.1; 7.6.2; 7.5.3; 7.7.2; 6.9.2; 7.9.1; 7.10.1; 7.8.2; 7.5.4; 6.5.33; 7.8.22; 7.7.21; 7.9.2; 7.3.5; 7.5.5; 7.11.1; 7.9.21; 7.10.2; 24.1.1; 7.6.3; 7.3.6; 7.5.52; 7.11.2; 24.2.1; 24.1.2; 24.2.11; 24.3.1; 24.4.1; 24.2.2; 7.8.23; 7.11.21; 24.2.20; 24.3.2; 24.4.10; 6.5.35; 25.1.1; 24.4.2; 24.3.20; 24.4.15; 6.5.351; 24.3.30; 6.5.352; 24.4.30	—	No fix listed	CNA

Cisco IOS XR Software VendorCisco Affected 6.5.3; 6.5.29; 6.5.1; 6.6.1; 6.5.2; 6.5.92; 6.5.15; 6.6.2; 7.0.1; 6.6.25; 6.5.26; 6.6.11; 6.5.25; 6.5.28; 6.5.93; 6.6.12; 6.5.90; 7.0.0; 7.1.1; 7.0.90; 6.6.3; 6.7.1; 7.0.2; 7.1.15; 7.2.0; 7.2.1; 7.1.2; 6.7.2; 7.0.11; 7.0.12; 7.0.14; 7.1.25; 6.6.4; 7.2.12; 7.3.1; 7.1.3; 6.7.3; 7.4.1; 7.2.2; 6.7.4; 6.5.31; 7.3.15; 7.3.16; 6.8.1; 7.4.15; 6.5.32; 7.3.2; 7.5.1; 7.4.16; 7.3.27; 7.6.1; 7.5.2; 7.8.1; 7.6.15; 7.5.12; 7.8.12; 7.3.3; 7.7.1; 6.8.2; 7.3.4; 7.4.2; 6.7.35; 6.9.1; 7.6.2; 7.5.3; 7.7.2; 6.9.2; 7.9.1; 7.10.1; 7.8.2; 7.5.4; 6.5.33; 7.8.22; 7.7.21; 7.9.2; 7.3.5; 7.5.5; 7.11.1; 7.9.21; 7.10.2; 24.1.1; 7.6.3; 7.3.6; 7.5.52; 7.11.2; 24.2.1; 24.1.2; 24.2.11; 24.3.1; 24.4.1; 24.2.2; 7.8.23; 7.11.21; 24.2.20; 24.3.2; 24.4.10; 6.5.35; 25.1.1; 24.4.2; 24.3.20; 24.4.15; 6.5.351; 24.3.30; 6.5.352; 24.4.30 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:o:cisco:ios_xr::::::::	—	—	Cisco

cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:* Versions — — ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2025-20340
2026-10-03 Alias added: GHSA-7xc2-hq29-896q
2026-10-23 EPSS moved to the 50th–90th percentile

References

Other 1

cisco-sa-iosxr-arp-storm-EjUU55yM

TI-2026-74174 Arbitrary file write in Cisco Secure Email Gateway via AMP feature KEVCVSS 3.1CRITICAL 9.8
TI-2026-53490 Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53489 Cisco Secure Email Gateway SQL Injection Vulnerability KEVCVSS 3.1CRITICAL 9.8
TI-2026-53488 Cisco Identity Services Engine Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16388 Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
TI-2026-16344 Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 10.0

See all 7059 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences