CVE-2009-2055

CRITICALNVD 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
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 3%CVSS: 5.9Exploit: cisa kev · ssvc activeExposed: 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)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
3%
EPSS %ILE
88%
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 57× in last 7d / 241× 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 733 total refreshes for this CVE.

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

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Frequently asked(6)

What is CVE-2009-2055?
CVE-2009-2055 is a critical 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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