CVE-2020-3118

CRITICALNVD 8.89.0
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 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.8 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 8.8 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

Also known asEUVD-2020-24389 (ENISA EUVD) · GHSA-f7vj-6cqm-9xgc (GitHub Security Advisories)Source: ENISA EUVD

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: 12%CVSS: 8.8Exploit: No code on recordExposed services: Not assessed

No fix has been recorded since the CVE record was published in 2020 — use a compensating control (WAF / firewall / segmentation) and check the vendor's advisory.

The CVE record's CNA (Cisco Systems, Inc.) lists Cisco IOS XR Software versions before 6.6.3 as affected. No release containing a fix is confirmed on record.

A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

CVSS v3
8.8
EG Score
9.0CRITICALhigh confidence
EG Risk
80
EG Risk 80/100

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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Attend at medium and Act at high mission impact.
Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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 2020. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low, sooner than that at medium and as soon as possible at high mission impact.
EPSS PROB
12%
EPSS %ILE
96th
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 8.8 HIGH.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
12% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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 impactTrack at low, Attend at medium and Act at high mission impact.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 14 days if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: this CVE is in CISA's KEV catalog, and CISA's required action for it, quoted below, applies whether or not a fix is released.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Attend at medium and Act at high mission impact.

No fix has been recorded since the CVE record was published in 2020. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low, sooner than that at medium and as soon as possible at high mission impact.

Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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 & forensic triage if the affected system is publicly exposed; 14 days if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: this CVE is in CISA's KEV catalog, and CISA's required action for it, quoted below, applies whether or not a fix is released.

The score's inputs: In CISA KEV yes (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (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-2020-3118

Published

February 5, 2020

Last Modified

October 28, 2025

Advisory Details (3)

Auto-updated Nov 2, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). No fix on record since 2020. 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-2020-3118
Web page

Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200205-iosxr-cdp-rce

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 126× 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 100 of 1,100 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. None are among the latest 100 rows. The 1,000 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 06:21 UTCEG score recompute
  2. 2026-11-02 06:21 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  3. 2026-11-01 06:26 UTCEG score recompute
  4. 2026-11-01 06:26 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  5. 2026-10-31 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  6. 2026-10-31 06:31 UTCEG score recompute
  7. 2026-10-31 06:31 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  8. 2026-10-30 16:29 UTCEPSS rescoreEPSS 12% · 96th percentile
  9. 2026-10-30 06:36 UTCEG score recompute
  10. 2026-10-30 06:36 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  11. 2026-10-29 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  12. 2026-10-29 06:41 UTCEG score recompute
  13. 2026-10-29 06:41 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  14. 2026-10-28 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  15. 2026-10-28 06:46 UTCEG score recompute
  16. 2026-10-28 06:46 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-10-27 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  18. 2026-10-27 06:52 UTCEG score recompute
  19. 2026-10-27 06:52 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  20. 2026-10-26 16:27 UTCEPSS rescoreEPSS 12% · 96th percentile
  21. 2026-10-26 06:57 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  22. 2026-10-25 18:44 UTCEG score recompute
  23. 2026-10-25 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  24. 2026-10-25 07:01 UTCEG score recompute
  25. 2026-10-25 07:01 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
Show 75 more
  1. 2026-10-24 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  2. 2026-10-24 07:05 UTCEG score recompute
  3. 2026-10-24 07:05 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  4. 2026-10-23 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  5. 2026-10-23 07:08 UTCEG score recompute
  6. 2026-10-23 07:08 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  7. 2026-10-22 16:29 UTCEPSS rescoreEPSS 12% · 96th percentile
  8. 2026-10-22 07:11 UTCEG score recompute
  9. 2026-10-22 07:11 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  10. 2026-10-21 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  11. 2026-10-21 07:16 UTCEG score recompute
  12. 2026-10-21 07:16 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  13. 2026-10-20 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  14. 2026-10-20 07:20 UTCEG score recompute
  15. 2026-10-20 07:20 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  16. 2026-10-19 16:27 UTCEPSS rescoreEPSS 12% · 96th percentile
  17. 2026-10-19 07:24 UTCEG score recompute
  18. 2026-10-19 07:23 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  19. 2026-10-18 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  20. 2026-10-18 07:27 UTCEG score recompute
  21. 2026-10-18 07:27 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  22. 2026-10-17 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  23. 2026-10-17 07:32 UTCEG score recompute
  24. 2026-10-17 07:32 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  25. 2026-10-16 16:33 UTCEPSS rescoreEPSS 12% · 96th percentile
  26. 2026-10-16 07:35 UTCEG score recompute
  27. 2026-10-16 07:35 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  28. 2026-10-15 16:27 UTCEPSS rescoreEPSS 12% · 96th percentile
  29. 2026-10-15 07:39 UTCEG score recompute
  30. 2026-10-15 07:39 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  31. 2026-10-14 16:28 UTCEPSS rescoreEPSS 12% · 96th percentile
  32. 2026-10-14 07:44 UTCEG score recompute
  33. 2026-10-14 07:44 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  34. 2026-10-13 16:28 UTCEPSS rescoreEPSS 12% · 95th percentile
  35. 2026-10-13 07:49 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  36. 2026-10-12 19:37 UTCEG score recompute
  37. 2026-10-12 16:29 UTCEPSS rescoreEPSS 12% · 95th percentile
  38. 2026-10-12 07:54 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  39. 2026-10-12 03:40 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  40. 2026-10-11 23:25 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  41. 2026-10-11 19:13 UTCEG score recompute
  42. 2026-10-11 19:13 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  43. 2026-10-11 15:00 UTCEG score recompute
  44. 2026-10-11 15:00 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  45. 2026-10-11 13:43 UTCEPSS rescoreEPSS 12% · 95th percentile
  46. 2026-10-11 10:47 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  47. 2026-10-11 06:35 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  48. 2026-10-11 02:22 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  49. 2026-10-10 22:08 UTCEG score recompute
  50. 2026-10-10 22:08 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  51. 2026-10-10 19:56 UTCEPSS rescoreEPSS 12% · 95th percentile
  52. 2026-10-10 17:47 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  53. 2026-10-10 13:34 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  54. 2026-10-10 09:23 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  55. 2026-10-10 05:10 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  56. 2026-10-10 00:57 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  57. 2026-10-09 20:45 UTCEG score recompute
  58. 2026-10-09 20:45 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  59. 2026-10-09 20:04 UTCEPSS rescoreEPSS 12% · 95th percentile
  60. 2026-10-09 16:33 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  61. 2026-10-09 12:22 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  62. 2026-10-09 08:10 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  63. 2026-10-09 03:58 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  64. 2026-10-08 23:45 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  65. 2026-10-08 19:33 UTCEG score recompute
  66. 2026-10-08 19:33 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  67. 2026-10-08 16:38 UTCEPSS rescoreEPSS 12% · 95th percentile
  68. 2026-10-08 15:20 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  69. 2026-10-08 11:08 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  70. 2026-10-08 06:56 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  71. 2026-10-08 02:44 UTCEG score recompute
  72. 2026-10-08 02:44 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  73. 2026-10-07 23:44 UTCEPSS rescoreEPSS 12% · 95th percentile
  74. 2026-10-07 22:31 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8
  75. 2026-10-07 18:18 UTCGHSA enrichmentGHSA-f7vj-6cqm-9xgc · GitHub severity HIGH · GitHub CVSS 8.8

Frequently asked(6)

What is CVE-2020-3118?
CVE-2020-3118 is a critical-severity vulnerability; its CVE record was published on February 5, 2020. A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in Cisco…
When was CVE-2020-3118 made public?
CVE-2020-3118 was made public on February 5, 2020: 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 February 5, 2020. EchelonGraph's copy of the record carries a last-modified date of October 28, 2025; the record at its source may have been updated since.
Is CVE-2020-3118 actively exploited?
Yes. CISA added CVE-2020-3118 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Cisco IOS XR. 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 2020. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation.
What is the CVSS score of CVE-2020-3118?
CVE-2020-3118 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2020-3118?
CVE-2020-3118 affects Cisco IOS XR.
How do I remediate CVE-2020-3118?
No fix for CVE-2020-3118 has been recorded since its CVE record was published in 2020. 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. The CVE record's CNA (Cisco Systems, Inc.) lists Cisco IOS XR Software versions before 6.6.3 as affected. No release containing a fix is confirmed on record.

Dependency Blast Radius

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