CVE-2026-76505 Cisco IOS XR Software - Denial of Service

Cisco IOS XR Software on Cisco ASR 9000, 9900 Series, and ASR 9902/9903 routers contains a denial of service vulnerability caused by incorrect handling of crafted IPv4 packets on line card interfaces, letting unauthenticated remote attackers cause line card resets or shutdowns, exploit requires crafted IPv4 packets targeting for-us traffic.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
21 October 2026
Updated
22 October 2026
Weakness
CWE-20

Vendor fix

Update to the latest Cisco IOS XR Software version that addresses this vulnerability.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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