CVE-2009-2055
Cisco IOS XR 3.4.0 through 3.8.1 allows remote attackers to cause a denial of service (session reset) via a BGP UPDATE message with an invalid attribute, as demonstrated in the wild on 17 August 2009.
Key facts
- CVSS score
- 5.9 (v3.1)
- Severity
- MEDIUM
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
- CWE-20
- EPSS score
- 3.3% (89th percentile)
- In CISA KEV
- Yes, added March 25, 2022
- In EU EUVD
- Yes (EUVD-2009-2051)
- Published
- August 19, 2009
- NVD last modified
- June 16, 2026
- Status
- Analyzed
CISA Known Exploited Vulnerability
Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability
Added to the KEV catalog on March 25, 2022; federal remediation due April 15, 2022.
EU Vulnerability Database (EUVD)
This vulnerability is also tracked by ENISA as EUVD-2009-2051 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on January 12, 2026.
View on the EU Vulnerability DatabaseAffected products
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
- cisco / ios xr
References
- http://mailman.nanog.org/pipermail/nanog/2009-August/012719.html(Mailing List)
- http://securitytracker.com/id?1022739(Broken Link)
- http://www.cisco.com/en/US/products/products_security_advisory09186a0080af150f.shtml(Patch, Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-2055(US Government Resource)
Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS
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