{"id":"CVE-2025-20115","title":"Cisco IOS XR Software Border Gateway Protocol Denial of Service Vulnerability","summary":"A vulnerability in confederation implementation for the Border Gateway Protocol (BGP) in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.\r\n\r\nThis vulnerability is due to a …","severity":"high","cvss":8.6,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","cvssSource":"vendor","vendor":"Cisco","product":"Cisco IOS XR Software","affected":["ios_xr_software"],"published":"2025-03-12","updated":"2025-03-12","sourceUpdated":"2025-03-12T16:00:00+00:00","source":"CSAF","sourceUrl":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-bgp-dos-O7stePhX","references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-bgp-dos-O7stePhX"},{"url":"https://software.cisco.com"}],"tags":["csaf","vendor-advisory","cisco","exploit-available"],"epss":0.00894,"epssPercentile":0.58185,"exploits":{"github":1,"githubRepos":["https://github.com/gduma-phData/patch-CVE-2025-20115"],"checkedAt":"2026-10-07T08:10:58.648Z"},"exploitAvailable":true,"ingestedAt":"2026-10-07T08:10:21.957Z","slug":"CVE-2025-20115","body":"## Overview\n\nA vulnerability in confederation implementation for the Border Gateway Protocol (BGP) in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.\r\n\r\nThis vulnerability is due to a memory corruption that occurs when a BGP update is created with an AS_CONFED_SEQUENCE attribute that has 255 autonomous system numbers (AS numbers). An attacker could exploit this vulnerability by sending a crafted BGP update message, or the network could be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more. A successful exploit could allow the attacker to cause memory corruption, which may cause the BGP process to restart, resulting in a DoS condition. To exploit this vulnerability, an attacker must control a BGP confederation speaker within the same autonomous system as the victim, or the network must be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more.\r\n\r\nCisco has released software updates that address this vulnerability. There is a workaround that addresses this vulnerability.\r\n\r\n\r\n\r\nThis advisory is part of the March 2025 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2025 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication [\"https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75548\"].\n\n## Vendor advisories\n\n- **cisco-sa-iosxr-bgp-dos-O7stePhX** · Cisco · affected: Cisco IOS XR Software · updated 2025-03-12 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-bgp-dos-O7stePhX)\n\n**Cisco IOS XR Software Border Gateway Protocol Confederation Denial of Service Vulnerability**. Released 2025-03-12.\n\nAffected:\n\n- Cisco IOS XR Software\n\n## Remediation\n\nCisco has released software updates that address this vulnerability. https://software.cisco.com","depth":"midnight","depthScore":59,"depthScoreParts":{"impact":47.3,"likelihood":0.2,"exploitation":12,"ransomware":0},"changes":[]}