CVE-2009-2055
Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability
- Medium 5.9
- Exploited: added to CISA KEV 25 Mar 2022
Description
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
- Published
- 19 Aug 2009
- Last changed
- 12 Jan 2026
- Assigned by
- cisco
- KEV added
- 25 Mar 2022
- KEV fix due
- 15 Apr 2022
- EPSS
- 3.314% likely to be exploited in the next 30 days, higher than 88.771% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: no; Technical impact: partial
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 5.9CVSS 3.1, Mediumfrom CISA (ADP container)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
What to do
- Apply updates per vendor instructions.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| n/a | n/a |
|
Timeline
- 19 Aug 2009 Published
- 25 Mar 2022 Added to the CISA KEV catalogue