CVE-2018-0156

CRITICALNVD 7.59.0
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.5 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: 9%CVSS: 7.5Exploit: cisa kev · ssvc activeExposed: 0

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

A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of packet data. An attacker could exploit this vulnerability by sending a crafted packet to an affected device on TCP port 4786. Only Smart Install client switches are affected. Cisco devices that are configured as a Smart Install director are not affected by this vulnerability. Cisco Bug IDs: CSCvd40673.

CVSS v3
7.5
EG Score
9.0(high)
EG Risk
96(Attend)
EG Risk 96/100SSVC: 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%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
9%
EPSS %ILE
95%
KEV
⚠ Exploited

Published

March 28, 2018

Last Modified

January 13, 2026

Advisory Details (3)

Auto-updated Jun 7, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

Cisco IOS and IOS XE Software Smart Install Denial of Service Vulnerability

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-smi

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 59× in last 7d / 252× 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 911 total refreshes for this CVE.

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

Frequently asked(6)

What is CVE-2018-0156?
CVE-2018-0156 is a critical vulnerability published on March 28, 2018. A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of packet data.…
When was CVE-2018-0156 disclosed?
CVE-2018-0156 was first published in the National Vulnerability Database on March 28, 2018, with the most recent update on January 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-0156 actively exploited?
Yes. CISA added CVE-2018-0156 to the Known Exploited Vulnerabilities catalog on March 3, 2022, affecting Cisco IOS Software and Cisco IOS XE Software. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2018-0156?
CVE-2018-0156 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2018-0156?
CVE-2018-0156 affects Cisco IOS Software and Cisco IOS XE Software. 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-2018-0156?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-0156, 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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