# CVE-2009-2055: Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability

> CVE-2009-2055: Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability. CVSS 5.9 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2009-2055
Last updated: 2026-01-12T20:39:47Z

- Published: 2009-08-19 17:00 UTC · Updated: 2026-01-12 20:39 UTC · Assigner: cisco
- CVSS: 5.9 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 3.3%, 88th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2022-03-25, federal due date 2022-04-15, ransomware use: Unknown

## 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.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Cisco: IOS XR

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2009-2055)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2009-2055)
- [http://mailman.nanog.org/pipermail/nanog/2009-August/012719.html](http://mailman.nanog.org/pipermail/nanog/2009-August/012719.html)
- [http://securitytracker.com/id?1022739](http://securitytracker.com/id?1022739)
- [http://www.cisco.com/en/US/products/products\_security\_advisory09186a0080af150f.shtml](http://www.cisco.com/en/US/products/products_security_advisory09186a0080af150f.shtml)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2009-2055 · Markdown: https://rewindex.com/cve/CVE-2009-2055.md · JSON: https://rewindex.com/api/v1/cves/CVE-2009-2055 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:47:38.545Z