CVE-2019-5544

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 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 9.8 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
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 97%CVSS: 9.8Exploit: cisa kev · ssvc active · kev ransomware · epss top5pct · epss high · public exploitExposed services: Not assessed

A fix is available — apply it.

OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue. VMware has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
99
EG Risk 99/100CISA SSVC

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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
CISA SSVC: Attend at low mission impact; Act at medium or high.
Action: A fix is available. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.
EPSS PROB
97%
EPSS %ILE
99th
KEV
⚠ Exploited

CISA SSVCAttend at low mission impact; Act at medium or high.

A fix is available. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

December 6, 2019

Last Modified

October 30, 2025

Advisory Details (8)

Auto-updated Oct 1, 2026
Patch available. Sources: redhat.
generic

oss-security - Re: CVE-2019-5544 openslp 1.2.1, 2.0.0 heap overflow vulnerability

http://www.openwall.com/lists/oss-security/2019/12/11/2
generic

oss-security - Re: CVE-2019-5544 openslp 1.2.1, 2.0.0 heap overflow vulnerability

http://www.openwall.com/lists/oss-security/2019/12/10/2
generic

OpenSLP: Multiple vulnerabilities (GLSA 202005-12) — Gentoo security

https://security.gentoo.org/glsa/202005-12
generic

[SECURITY] Fedora 31 Update: openslp-2.0.0-23.fc31 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZPXXJZLPLAQULBCJVI5NNWZ3PGWXGXWG/
generic

[SECURITY] Fedora 30 Update: openslp-2.0.0-22.fc30 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA3LYAJ2NRKMOZLZOQNDJ5TNQRFMWGHF/
redhat Patch Available

Affected: Red Hat Enterprise Linux 6.

https://access.redhat.com/errata/RHSA-2020:0199
redhat Patch Available

Affected: Red Hat Enterprise Linux 7.

https://access.redhat.com/errata/RHSA-2019:4240
generic

Support Content Notification - Support Portal - Broadcom support portal

http://www.vmware.com/security/advisories/VMSA-2019-0022.html

Vendor Advisories for CVE-2019-5544(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuslptool (1.2.1-11ubuntu0.16.04.2) @ xenial2026-10-04ubuntu
redhatopenslp-1:2.0.0-4.el6_102020-01-22redhat
redhatopenslp-1:2.0.0-8.el7_72019-12-16redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Debian:8(1)
PackageVulnerable rangeFixed inDependents
openslp-dfsg1.2.1-10, 1.2.1-10+deb8u11.2.1-10+deb8u2—

Weakness Classification(1)

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

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 87× in last 7d / 392× 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 1,611 total refreshes for this CVE.

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

Publicly available exploits

(3 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCdgh05t/VMware_ESXI_OpenSLP_PoCs
    First seen Feb 4, 2021

    CVE-2020-3992 & CVE-2019-5544

    Open source ↗
  • GitHub PoCHynekPetrak/CVE-2019-5544_CVE-2020-3992
    First seen Dec 1, 2020

    Python / scapy module implementing SRVLOC/SLP protocol and scans for enabled OpenSLP services.

    Open source ↗
  • Nucleinetwork/cves/2019/CVE-2019-5544.yaml
    First seen Jan 1, 2019

    VMware ESXi SLP - Heap Overflow DoS

    Open source ↗

Related CVEs(same product + same CWE)

Frequently asked(6)

What is CVE-2019-5544?
CVE-2019-5544 is a critical vulnerability published on December 6, 2019. OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue. VMware has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.
When was CVE-2019-5544 disclosed?
CVE-2019-5544 was first published on December 6, 2019, with the most recent update on October 30, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2019-5544 actively exploited?
Yes. CISA added CVE-2019-5544 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting VMware VMware ESXi and Horizon DaaS. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2019-5544?
CVE-2019-5544 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2019-5544?
CVE-2019-5544 affects VMware VMware ESXi and Horizon DaaS. The affected packages EchelonGraph has on record, with version ranges, are listed in the Affected Packages section of this page.
How do I remediate CVE-2019-5544?
A fix for CVE-2019-5544 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2019-5544 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2019-5544

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