CVE-2018-0159

CRITICALNVD 7.59.0
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than NVD's CVSS score.

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. The 9.0 is the floor for confirmed exploitation, not an impact rating: this CVE's impact severity (EG Severity) is CVSS 7.5 HIGH under GitHub Security Advisory CVSS. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictMitigate nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low or medium mission impact
CISA-KEV: ExploitedEPSS PROB: 6.9%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

No fix has been recorded since the CVE record was published in 2018 — use a compensating control (WAF / firewall / segmentation) and check the vendor's advisory.

A vulnerability in the implementation of Internet Key Exchange Version 1 (IKEv1) functionality in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of specific IKEv1 packets. An attacker could exploit this vulnerability by sending crafted IKEv1 packets to an affected device during an IKE negotiation. A successful exploit could allow the attacker to cause an affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuj73916.

CVSS v3
7.5
EG Score
9.0CRITICALhigh confidence
EG Risk
89
EG Risk 89/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Attend at low or medium mission impact; Act at high (mission-essential systems).
Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: No fix has been recorded since the CVE record was published in 2018. Restrict network exposure of the affected system or apply the vendor's mitigation sooner than your standard update timelines at low or medium mission impact and as soon as possible at high, and check the vendor's advisory for a fix.
EPSS PROB
6.9%
EPSS %ILE
94th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is the CISA KEV floor for confirmed exploitation, not an impact rating: its impact severity (EG Severity) is CVSS 7.5 HIGH.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
6.9% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-23). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Attend at medium mission impactAttend at low or medium mission impact; Act at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 14 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Attend at low or medium mission impact; Act at high (mission-essential systems).

No fix has been recorded since the CVE record was published in 2018. Restrict network exposure of the affected system or apply the vendor's mitigation sooner than your standard update timelines at low or medium mission impact and as soon as possible at high, and check the vendor's advisory for a fix.

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 14 days if it is not.

In CISA KEV yes (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

CISA required action“Apply updates per vendor instructions.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://nvd.nist.gov/vuln/detail/CVE-2018-0159

Published

March 28, 2018

Last Modified

January 14, 2026

Advisory Details (4)

Auto-updated Oct 20, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). No fix on record since 2018. Sources: cisa.
CISA🔴 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-2018-0159
Web page

Cisco IOS and IOS XE Software Internet Key Exchange Version 1 Denial of Service Vulnerability

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-ike-dos
Web page

CVE-2018-0159 - PSIRT.COM

http://www.securityfocus.com/bid/103562

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 191× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 1,140 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 1,041 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-23 16:54 UTCEG score recompute
  2. 2026-10-23 16:54 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  3. 2026-10-23 16:27 UTCEPSS rescoreEPSS 6.9% · 94th percentile
  4. 2026-10-22 16:27 UTCEPSS rescoreEPSS 6.9% · 94th percentile
  5. 2026-10-22 16:11 UTCEG score recompute
  6. 2026-10-22 16:11 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  7. 2026-10-21 16:27 UTCEPSS rescoreEPSS 6.9% · 94th percentile
  8. 2026-10-21 15:26 UTCEG score recompute
  9. 2026-10-21 15:26 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  10. 2026-10-20 16:27 UTCEPSS rescoreEPSS 6.9% · 94th percentile
  11. 2026-10-20 14:43 UTCEG score recompute
  12. 2026-10-20 14:43 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  13. 2026-10-19 16:26 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  14. 2026-10-19 14:01 UTCEG score recompute
  15. 2026-10-19 14:00 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  16. 2026-10-18 16:27 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  17. 2026-10-18 13:16 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  18. 2026-10-18 10:25 UTCEG score recompute
  19. 2026-10-17 16:27 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  20. 2026-10-17 12:32 UTCEG score recompute
  21. 2026-10-17 12:32 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  22. 2026-10-16 16:29 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  23. 2026-10-16 11:49 UTCEG score recompute
  24. 2026-10-16 11:49 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  25. 2026-10-15 16:27 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
Show 74 more
  1. 2026-10-15 11:06 UTCEG score recompute
  2. 2026-10-15 11:05 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  3. 2026-10-14 16:27 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  4. 2026-10-14 10:20 UTCEG score recompute
  5. 2026-10-14 10:20 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  6. 2026-10-13 16:27 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  7. 2026-10-13 09:37 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  8. 2026-10-12 20:23 UTCEG score recompute
  9. 2026-10-12 16:28 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  10. 2026-10-12 08:52 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  11. 2026-10-12 05:00 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  12. 2026-10-12 01:07 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  13. 2026-10-11 21:13 UTCEG score recompute
  14. 2026-10-11 21:13 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  15. 2026-10-11 17:19 UTCEG score recompute
  16. 2026-10-11 17:18 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  17. 2026-10-11 13:41 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  18. 2026-10-11 13:24 UTCEG score recompute
  19. 2026-10-11 13:24 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  20. 2026-10-11 09:31 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  21. 2026-10-11 05:36 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  22. 2026-10-11 01:44 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  23. 2026-10-10 21:50 UTCEG score recompute
  24. 2026-10-10 21:50 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  25. 2026-10-10 19:55 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  26. 2026-10-10 17:58 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  27. 2026-10-10 14:04 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  28. 2026-10-10 10:12 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  29. 2026-10-10 06:20 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  30. 2026-10-10 02:27 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  31. 2026-10-09 22:36 UTCEG score recompute
  32. 2026-10-09 22:36 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  33. 2026-10-09 20:02 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  34. 2026-10-09 18:43 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  35. 2026-10-09 14:51 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  36. 2026-10-09 10:57 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  37. 2026-10-09 07:05 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  38. 2026-10-09 03:12 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  39. 2026-10-08 23:20 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  40. 2026-10-08 19:28 UTCEG score recompute
  41. 2026-10-08 19:28 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  42. 2026-10-08 16:36 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  43. 2026-10-08 15:35 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  44. 2026-10-08 11:43 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  45. 2026-10-08 07:51 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  46. 2026-10-08 03:59 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  47. 2026-10-08 00:06 UTCEG score recompute
  48. 2026-10-08 00:06 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  49. 2026-10-07 23:41 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  50. 2026-10-07 20:14 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  51. 2026-10-07 16:22 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  52. 2026-10-07 12:29 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  53. 2026-10-07 08:37 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  54. 2026-10-07 04:45 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  55. 2026-10-07 00:53 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  56. 2026-10-06 21:00 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  57. 2026-10-06 17:06 UTCEG score recompute
  58. 2026-10-06 17:06 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  59. 2026-10-06 15:12 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  60. 2026-10-06 13:14 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  61. 2026-10-06 09:22 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  62. 2026-10-06 05:30 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  63. 2026-10-06 01:34 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  64. 2026-10-05 21:42 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  65. 2026-10-05 17:48 UTCEG score recompute
  66. 2026-10-05 17:48 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  67. 2026-10-05 17:39 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  68. 2026-10-05 13:56 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  69. 2026-10-05 10:04 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  70. 2026-10-05 06:12 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  71. 2026-10-05 02:20 UTCEG score recompute
  72. 2026-10-05 02:20 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5
  73. 2026-10-04 23:18 UTCEPSS rescoreEPSS 6.9% · 93rd percentile
  74. 2026-10-04 22:28 UTCGHSA enrichmentGHSA-p7j7-5cqq-j6m7 · GitHub severity HIGH · GitHub CVSS 7.5

Frequently asked(6)

What is CVE-2018-0159?
CVE-2018-0159 is a critical-severity vulnerability; its CVE record was published on March 28, 2018. A vulnerability in the implementation of Internet Key Exchange Version 1 (IKEv1) functionality in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability…
When was CVE-2018-0159 made public?
CVE-2018-0159 was made public on March 28, 2018: that is the date its CVE record's CNA, Cisco Systems, Inc., gives for when the vulnerability was made public. The CVE record itself was published on March 28, 2018. EchelonGraph's copy of the record carries a last-modified date of January 14, 2026; the record at its source may have been updated since.
Is CVE-2018-0159 actively exploited?
Yes. CISA added CVE-2018-0159 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 attention. No fix has been recorded since the CVE record was published in 2018. Restrict network exposure of the affected system or apply the vendor's mitigation, and check the vendor's advisory for a fix.
What is the CVSS score of CVE-2018-0159?
CVE-2018-0159 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 (CRITICAL).
Which products are affected by CVE-2018-0159?
CVE-2018-0159 affects Cisco IOS Software and Cisco IOS XE Software.
How do I remediate CVE-2018-0159?
No fix for CVE-2018-0159 has been recorded since its CVE record was published in 2018. Restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and check the vendor's advisory for a fix.

Dependency Blast Radius

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