CVE-2009-2055

MEDIUMNVD 5.99.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-03-25), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 5.9 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
5.9
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 3%CVSS: 5.9Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
5.9
EG Score
9.0(high)
EPSS
87.1%
KEV
⚠ Exploited

Published

August 19, 2009

Last Modified

April 22, 2026

Advisory Details (2)

Auto-updated May 20, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2009-2055
generic
http://securitytracker.com/id?1022739

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 96× in last 7d / 423× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 576 total refreshes for this CVE.

  1. 2026-07-07 22:50 UTCEG score recompute
  2. 2026-07-07 22:49 UTCGHSA enrichment
  3. 2026-07-07 19:01 UTCCISA KEV update
  4. 2026-07-07 18:57 UTCEG score recompute
  5. 2026-07-07 18:57 UTCGHSA enrichment
  6. 2026-07-07 17:16 UTCCISA KEV update
  7. 2026-07-07 15:04 UTCEG score recompute
  8. 2026-07-07 15:04 UTCGHSA enrichment
  9. 2026-07-07 11:04 UTCEG score recompute
  10. 2026-07-07 11:04 UTCGHSA enrichment
  11. 2026-07-07 07:11 UTCEG score recompute
  12. 2026-07-07 07:11 UTCGHSA enrichment
  13. 2026-07-07 03:17 UTCEG score recompute
  14. 2026-07-07 03:17 UTCGHSA enrichment
  15. 2026-07-06 23:25 UTCEG score recompute
  16. 2026-07-06 23:25 UTCGHSA enrichment
  17. 2026-07-06 19:32 UTCEG score recompute
  18. 2026-07-06 19:31 UTCGHSA enrichment
  19. 2026-07-06 16:23 UTCEPSS rescore
  20. 2026-07-06 15:38 UTCEG score recompute
  21. 2026-07-06 15:38 UTCGHSA enrichment
  22. 2026-07-06 11:44 UTCEG score recompute
  23. 2026-07-06 11:44 UTCGHSA enrichment
  24. 2026-07-06 07:52 UTCEG score recompute
  25. 2026-07-06 07:52 UTCGHSA enrichment
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  1. 2026-07-06 03:59 UTCEG score recompute
  2. 2026-07-06 03:59 UTCGHSA enrichment
  3. 2026-07-06 02:19 UTCEPSS rescore
  4. 2026-07-06 02:19 UTCEPSS rescore
  5. 2026-07-06 00:07 UTCEG score recompute
  6. 2026-07-06 00:07 UTCGHSA enrichment
  7. 2026-07-05 20:13 UTCEG score recompute
  8. 2026-07-05 20:13 UTCGHSA enrichment
  9. 2026-07-05 16:20 UTCEG score recompute
  10. 2026-07-05 16:20 UTCGHSA enrichment
  11. 2026-07-05 12:28 UTCEG score recompute
  12. 2026-07-05 12:28 UTCGHSA enrichment
  13. 2026-07-05 08:36 UTCEG score recompute
  14. 2026-07-05 08:36 UTCGHSA enrichment
  15. 2026-07-05 04:43 UTCEG score recompute
  16. 2026-07-05 04:43 UTCGHSA enrichment
  17. 2026-07-05 02:26 UTCEPSS rescore
  18. 2026-07-05 02:26 UTCEPSS rescore
  19. 2026-07-05 00:46 UTCEG score recompute
  20. 2026-07-05 00:45 UTCGHSA enrichment
  21. 2026-07-04 20:53 UTCEG score recompute
  22. 2026-07-04 20:53 UTCGHSA enrichment
  23. 2026-07-04 17:00 UTCEG score recompute
  24. 2026-07-04 17:00 UTCGHSA enrichment
  25. 2026-07-04 13:07 UTCEG score recompute
  26. 2026-07-04 13:07 UTCGHSA enrichment
  27. 2026-07-04 09:14 UTCEG score recompute
  28. 2026-07-04 09:14 UTCGHSA enrichment
  29. 2026-07-04 06:27 UTCEPSS rescore
  30. 2026-07-04 05:21 UTCEG score recompute
  31. 2026-07-04 05:21 UTCGHSA enrichment
  32. 2026-07-04 01:29 UTCEG score recompute
  33. 2026-07-04 01:28 UTCGHSA enrichment
  34. 2026-07-03 21:36 UTCEG score recompute
  35. 2026-07-03 21:36 UTCGHSA enrichment
  36. 2026-07-03 17:43 UTCEG score recompute
  37. 2026-07-03 17:43 UTCGHSA enrichment
  38. 2026-07-03 13:51 UTCEG score recompute
  39. 2026-07-03 13:51 UTCGHSA enrichment
  40. 2026-07-03 09:59 UTCEG score recompute
  41. 2026-07-03 09:59 UTCGHSA enrichment
  42. 2026-07-03 06:06 UTCEG score recompute
  43. 2026-07-03 06:06 UTCGHSA enrichment
  44. 2026-07-03 02:11 UTCEG score recompute
  45. 2026-07-03 02:11 UTCGHSA enrichment
  46. 2026-07-02 22:19 UTCEG score recompute
  47. 2026-07-02 22:19 UTCGHSA enrichment
  48. 2026-07-02 18:26 UTCEG score recompute
  49. 2026-07-02 18:25 UTCGHSA enrichment
  50. 2026-07-02 14:33 UTCEG score recompute
  51. 2026-07-02 14:33 UTCGHSA enrichment
  52. 2026-07-02 10:40 UTCEG score recompute
  53. 2026-07-02 10:39 UTCGHSA enrichment
  54. 2026-07-02 06:44 UTCEG score recompute
  55. 2026-07-02 06:44 UTCGHSA enrichment
  56. 2026-07-02 02:52 UTCEG score recompute
  57. 2026-07-02 02:52 UTCGHSA enrichment
  58. 2026-07-01 22:59 UTCEG score recompute
  59. 2026-07-01 22:59 UTCGHSA enrichment
  60. 2026-07-01 19:16 UTCCISA KEV update
  61. 2026-07-01 19:06 UTCEG score recompute
  62. 2026-07-01 19:06 UTCGHSA enrichment
  63. 2026-07-01 15:12 UTCEG score recompute
  64. 2026-07-01 15:12 UTCGHSA enrichment
  65. 2026-07-01 15:02 UTCEPSS rescore
  66. 2026-07-01 11:20 UTCEG score recompute
  67. 2026-07-01 11:20 UTCGHSA enrichment
  68. 2026-07-01 07:28 UTCEG score recompute
  69. 2026-07-01 07:28 UTCGHSA enrichment
  70. 2026-07-01 03:36 UTCEG score recompute
  71. 2026-07-01 03:36 UTCGHSA enrichment
  72. 2026-06-30 23:44 UTCEG score recompute
  73. 2026-06-30 23:44 UTCGHSA enrichment
  74. 2026-06-30 23:19 UTCEPSS rescore
  75. 2026-06-30 19:46 UTCEG score recompute

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Frequently asked(6)

What is CVE-2009-2055?
CVE-2009-2055 is a medium vulnerability published on August 19, 2009. 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.
When was CVE-2009-2055 disclosed?
CVE-2009-2055 was first published in the National Vulnerability Database on August 19, 2009, with the most recent update on April 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2009-2055 actively exploited?
Yes. CISA added CVE-2009-2055 to the Known Exploited Vulnerabilities catalog on March 25, 2022, affecting Cisco IOS XR. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2009-2055?
CVE-2009-2055 has a CVSS v3 base score of 5.9 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2009-2055?
CVE-2009-2055 affects Cisco IOS XR. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2009-2055?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2009-2055, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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