CVE-2019-5591

CRITICALNVD 6.59.0
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 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 6.5 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 6.5 MEDIUM 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-2019-15166 (ENISA EUVD) · GHSA-p9g8-h33v-mg42 (GitHub Security Advisories)Source: ENISA EUVD

9.0EG
EchelonGraph verdictMitigate nowTreat as an emergency — this is being exploited.
  • 80 internet-facing services (distinct ip:port) on record running an affected version — derived from Shodan data (© Shodan); a patched service can stay counted while its port stays open
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at every mission impact level
  • Linked to ransomware campaigns
CISA-KEV: ExploitedEPSS PROB: 19%CVSS: 6.5Exploit: No code on recordExposed services: 80

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.

A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.

Internet exposure · derived from Shodan data

80 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2019-5591, in our KEV-Exposure radar’s Shodan-derived sample.

across 19 countries (United States, Italy, Canada, India, Switzerland)top: fortios🔒 ransomware-linked
See the KEV-Exposure radar →Derived from Shodan data. Shodan data is owned by Shodan, which holds its copyright (© Shodan). EchelonGraph claims no ownership of it or copyright in it. Aggregate, host-redacted.

How it counts: every 12 hours, when Shodan query credits allow, the radar runs one Shodan query per tracked product, reads up to 100 ip:port services per query, and keeps a service when its banner version matches a CISA-KEV or high-EPSS CVE; a service is dropped when neither a search nor a Shodan InternetDB port re-check has refreshed it for 21 days. A re-check that finds the port still listed by Shodan InternetDB refreshes the service without re-reading the banner, so a patched service can stay counted while its port stays open. A count is a banner-version inference over a sample, not an exploit test and not an internet-wide census, and the unit is a service, not a machine: a machine answering on two ports counts twice.

CVSS v3
6.5
EG Score
9.0CRITICALhigh confidence
EG Risk
69
EG Risk 69/100

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)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation active (CISA Vulnrichment) · Automatable no (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 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 or medium mission impact and sooner than that at high.
EPSS PROB
19%
EPSS %ILE
97th
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 6.5 MEDIUM.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
19% 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 Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days 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 or medium mission impact; Attend at high (mission-essential systems).

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 or medium mission impact and sooner than that at high.

Exploitation active (CISA Vulnrichment) · Automatable no (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)14 days 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 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-2019-5591

Published

August 14, 2020

Last Modified

August 15, 2026

Advisory Details (2)

Auto-updated Oct 27, 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-2019-5591
Web page

PSIRT | FortiGuard Labs

https://www.fortiguard.com/psirt/FG-IR-19-037

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 124× 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 1,062 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 962 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 20:18 UTCEG score recompute
  2. 2026-11-01 20:18 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub severity MODERATE · GitHub CVSS 6.5
  3. 2026-10-31 20:53 UTCEG score recompute
  4. 2026-10-31 20:53 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  5. 2026-10-31 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
  6. 2026-10-30 21:29 UTCEG score recompute
  7. 2026-10-30 21:29 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  8. 2026-10-30 16:29 UTCEPSS rescoreEPSS 19% · 97th percentile
  9. 2026-10-29 22:05 UTCEG score recompute
  10. 2026-10-29 22:05 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  11. 2026-10-29 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
  12. 2026-10-28 22:40 UTCEG score recompute
  13. 2026-10-28 22:40 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  14. 2026-10-28 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  15. 2026-10-27 23:16 UTCEG score recompute
  16. 2026-10-27 23:16 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  17. 2026-10-27 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  18. 2026-10-26 23:48 UTCEG score recompute
  19. 2026-10-26 23:48 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  20. 2026-10-26 00:23 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  21. 2026-10-25 18:57 UTCEG score recompute
  22. 2026-10-25 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  23. 2026-10-25 00:58 UTCEG score recompute
  24. 2026-10-25 00:58 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  25. 2026-10-24 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
Show 75 more
  1. 2026-10-24 01:34 UTCEG score recompute
  2. 2026-10-24 01:34 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  3. 2026-10-23 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  4. 2026-10-23 02:09 UTCEG score recompute
  5. 2026-10-23 02:09 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  6. 2026-10-22 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
  7. 2026-10-22 02:44 UTCEG score recompute
  8. 2026-10-22 02:43 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  9. 2026-10-21 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  10. 2026-10-21 03:16 UTCEG score recompute
  11. 2026-10-21 03:16 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  12. 2026-10-20 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
  13. 2026-10-20 03:51 UTCEG score recompute
  14. 2026-10-20 03:51 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  15. 2026-10-19 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  16. 2026-10-19 04:26 UTCEG score recompute
  17. 2026-10-19 04:26 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  18. 2026-10-18 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  19. 2026-10-18 05:01 UTCEG score recompute
  20. 2026-10-18 05:01 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  21. 2026-10-17 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
  22. 2026-10-17 05:37 UTCEG score recompute
  23. 2026-10-17 05:37 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  24. 2026-10-16 16:32 UTCEPSS rescoreEPSS 19% · 97th percentile
  25. 2026-10-16 06:12 UTCEG score recompute
  26. 2026-10-16 06:11 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  27. 2026-10-15 16:27 UTCEPSS rescoreEPSS 19% · 97th percentile
  28. 2026-10-15 06:46 UTCEG score recompute
  29. 2026-10-15 06:46 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  30. 2026-10-14 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
  31. 2026-10-14 07:20 UTCEG score recompute
  32. 2026-10-14 07:20 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  33. 2026-10-13 16:28 UTCEPSS rescoreEPSS 19% · 97th percentile
  34. 2026-10-13 07:54 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  35. 2026-10-12 19:53 UTCEG score recompute
  36. 2026-10-12 08:28 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  37. 2026-10-12 04:05 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  38. 2026-10-11 23:40 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  39. 2026-10-11 19:18 UTCEG score recompute
  40. 2026-10-11 19:17 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  41. 2026-10-11 14:55 UTCEG score recompute
  42. 2026-10-11 14:55 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  43. 2026-10-11 13:42 UTCEPSS rescoreEPSS 19% · 97th percentile
  44. 2026-10-11 10:32 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  45. 2026-10-11 06:07 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  46. 2026-10-11 01:43 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  47. 2026-10-10 21:20 UTCEG score recompute
  48. 2026-10-10 21:20 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  49. 2026-10-10 19:56 UTCEPSS rescoreEPSS 19% · 97th percentile
  50. 2026-10-10 16:57 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  51. 2026-10-10 12:33 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  52. 2026-10-10 08:11 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  53. 2026-10-10 03:48 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  54. 2026-10-09 23:27 UTCEG score recompute
  55. 2026-10-09 23:27 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  56. 2026-10-09 20:03 UTCEPSS rescoreEPSS 19% · 97th percentile
  57. 2026-10-09 19:04 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  58. 2026-10-09 14:40 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  59. 2026-10-09 10:16 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  60. 2026-10-09 05:53 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  61. 2026-10-09 01:31 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  62. 2026-10-08 21:08 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  63. 2026-10-08 16:46 UTCEG score recompute
  64. 2026-10-08 16:46 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  65. 2026-10-08 16:37 UTCEPSS rescoreEPSS 19% · 97th percentile
  66. 2026-10-08 12:24 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  67. 2026-10-08 08:02 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  68. 2026-10-08 03:39 UTCEG score recompute
  69. 2026-10-08 03:39 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  70. 2026-10-07 23:43 UTCEPSS rescoreEPSS 18% · 97th percentile
  71. 2026-10-07 23:17 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  72. 2026-10-07 18:55 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  73. 2026-10-07 14:33 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  74. 2026-10-07 10:11 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5
  75. 2026-10-07 05:49 UTCGHSA enrichmentGHSA-p9g8-h33v-mg42 · GitHub CVSS 6.5

Public detection templates

(1 reference)

A public Nuclei detection template is referenced for this CVE. A detection template checks whether a system is affected; it is not necessarily exploit code.

  • Nucleihttp/cves/2019/CVE-2019-5591.yaml
    Published Dec 22, 2025

    FortiOS - Insecure LDAP Configuration Detection

    Open source ↗

Frequently asked(6)

What is CVE-2019-5591?
CVE-2019-5591 is a critical-severity vulnerability; its CVE record was published on August 14, 2020. A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
When was the CVE record for CVE-2019-5591 published?
The CVE record for CVE-2019-5591 was published on August 14, 2020. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 15, 2026; the record at its source may have been updated since.
Is CVE-2019-5591 actively exploited?
Yes. CISA added CVE-2019-5591 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Fortinet FortiOS. 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-2019-5591?
CVE-2019-5591 has a CVSS v3 base score of 6.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2019-5591?
CVE-2019-5591 affects Fortinet FortiOS.
How do I remediate CVE-2019-5591?
No fix for CVE-2019-5591 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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2019-5591

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