CVE-2009-2055Cisco 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.
Updated under an hour ago ()
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It affects cisco ios_xr. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Mar 25, 2022; federal agencies had to remediate by Apr 15, 2022. Treat that date as your deadline.
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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.
- CVSS
- 5.9 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-20
- Known exploited
- Added to CISA KEV Mar 25, 2022; federal remediation due Apr 15, 2022Apply updates per vendor instructions.
- EPSS (exploitation in the next 30 days)
- 3.31% (percentile 88)
- Assigned by
- cisco
- NVD analysis
- Analyzed
- Record last updated
- Jan 12, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
cisco ios_xr cisco:ios_xr | 3.4; 3.4.0; 3.4.1; 3.4.2; 3.4.3; 3.5; 3.5.2; 3.5.3; and 11 more ranges | NVD |
References
- http://mailman.nanog.org/pipermail/nanog/2009-August/012719.htmlmailing-list, x-refsource-mlist
- http://securitytracker.com/id?1022739vdb-entry, x-refsource-sectrack, broken-link
- http://www.cisco.com/en/US/products/products_security_advisory09186a0080af150f.shtmlvendor-advisory, x-refsource-cisco, patch
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-2055us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.