vciy

CVE-2019-5544

INDEX BUILT · 2026-09-20

No source can show you its own past. This one can.

Print this page to keep the view as it stands on this date. Everything hidden behind a disclosure opens, and every receipt prints with its value.

OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue

CVE-2019-55444 of 4 sources documented this
81

rank 81 = 40 + 25 + 0 + 10 + 6

rank@v1 · act now

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.97258 · CISA KEV listed  ·  without this subject the record ranks 41

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 9.8, from NVD  ·  without this subject the record ranks 56

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

no persisting rise in 365 days  ·  without this subject the record ranks 81

How much of the world it touches

NVD CPE configurations

20 products in the CPE ranges  ·  without this subject the record ranks 71

Someone else already set the date

CISA KEV remediation due date

CISA remediation date held  ·  without this subject the record ranks 75

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$4.85Mover the next 30 days, if this record is yours
Movement+$371,000on 2025-07-21, the last material move, 1 year, 1 month before this reading
Basisassumeda published average, not your estate

$4.85M = $4.99M incident cost x 1 exposure x 0.97258 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.97258EPSSKEV · LISTED
Severity9.8 CRITICALreceipt
Harmtotal loss · unauthenticated · ransomware-linkedreceipt
Exploitationransomware use knownreceipt
Defenseunaffected versions publishedreceipt
Movementrisenreceipt
PLATEAU10Minimal movement since 2025-07-21, 410 days at 0.97, as of 2026-09-04. arc-rules@v1

Foresight · where to check next

FortinetFortinetSonicWall SMA100Google ChromeIvanti Connect5544

This record is one instance of CWE-787, out-of-bounds write. The index holds 14892 prior instances of this class, 163 KEV-listed. The nearest of its KEV-listed records are drawn beside this. taxonomy@v1

Full pattern panel

Prior records in this weakness class. Each is its own record, dated and receipted.
Color is a claim, not decoration:the hostile worldthe defenseno signalspoke length is how much of the record matches, not how bad it is

Running ESXi and Horizon DaaS? Check your version

A deterministic range check against the ranges this record publishes. It tells you where a version sits in the record, not whether your deployment is exploitable. No account needed.

Watch this record

Matches your own product list against every record this index holds, and tells you when one of them moves.

What counts as a move

Set up a watchlist (needs a Practitioner account)

Record your call

Keep your verdict, your reason and the evidence together. The record takes its date when you save it.

AcceptDeferPatch by…Not affectedMitigated

Choose your verdict, then sign in or use an email link. Your first 100 records are free. Evidence is frozen when the record is created.

Private to your organization unless you share it. Put the proof link in your ticket so a reviewer can inspect the basis for your call. See how decision records work.

Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachnetwork-reachable · no privileges required · no user interaction · low attack complexityreceipt
ImpactComplete confidentiality, integrity and availability lossreceipt
Scored fromCVSS v3.1 · NVD's vectorreceipt
Weakness classCWE-787 Out-of-bounds Writereceipt
Published consequencesCWE-787: Integrity: Modify Memory, Execute Unauthorized Code or Commands; Availability: DoS: Crash, Exit, or Restart; Other: Unexpected State[email protected]
Ransomware campaign useKnown (CISA)receipt

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

First unaffected version, by branchhorizon daas 9.0.0.0receipt
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.
CISA remediation statusoverdue since 2022-05-03receipt
CISA required actionApply updates per vendor instructions.receipt
Published to CISA KEV698 daysderived

Exploit Status & Known PoCs a ladder, not a score

Current rung: Ransomware campaign use known, 2021-11-03.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 2 public repositories2020-12-01receipt
  • RUNG 3Exploited in the wild · CISA KEV listed2021-11-03receipt
  • RUNG 4Ransomware campaign use known2021-11-03receipt

Authority who says so

CVSS, NVD9.8 CRITICALreceipt
Exploit probability0.97258 · top 0.11% of all CVEsreceipt
Blast breadth14 products across 2 vendorsderived
Assigned byvmwarereceipt
Recorded changes47 · last 18 Sep 2026derived

Affected & Fixed Versions as published

Affected productESXi and Horizon DaaSreceipt
Published rangesvmware horizon daas >= 8.0.0 < 9.0.0.0; vmware esxi 6.0; vmware esxi 6.5; vmware esxi 6.7receipt
Show all 20 published ranges
vmware horizon daas >= 8.0.0 < 9.0.0.0
vmware esxi 6.0
vmware esxi 6.5
vmware esxi 6.7
redhat enterprise linux desktop 6.0
redhat enterprise linux desktop 7.0
redhat enterprise linux for ibm z systems 6.0_s390x
redhat enterprise linux for ibm z systems 7.0_s390x
redhat enterprise linux for ibm z systems eus 7.7_s390x
redhat enterprise linux for power big endian 6.0_ppc64
redhat enterprise linux for power big endian 7.0_ppc64
redhat enterprise linux for power big endian eus 7.7_ppc64
redhat enterprise linux for power little endian 7.0_ppc64le
redhat enterprise linux for power little endian eus 7.7_ppc64le
redhat enterprise linux server 6.0
redhat enterprise linux server 7.0
redhat enterprise linux server aus 7.7
redhat enterprise linux server eus 7.7
redhat enterprise linux server tus 7.7
redhat enterprise linux workstation 6.0

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

Did this affect your environment?Answering needs an account.

What it is stated by the CNA

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. receipt

NVD's analysis a second authority

severity
9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
weakness
CWE-787
affected versions
vmware horizon daas >= 8.0.0 < 9.0.0.0; vmware esxi 6.0; vmware esxi 6.5; and 17 more, listed in full below
also scored by
9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

check it yourself vmware.com openwall.com openwall.com access.redhat.com lists.fedoraproject.org lists.fedoraproject.org +2 morereceipt

Dated events

2021-11-03Added to CISA KEV2022-02-04EPSS moved 0.08 to 0.202022-05-03CISA remediation due2025-03-17EPSS moved 0.20 to 0.902025-07-21EPSS moved 0.85 to 0.93

Movement the material steps

14 Apr 20210.07855
4 Feb 20220.20148 · crossed 0.10
7 Mar 20230.09322 · crossed 0.10 · scoring model v2023.03.01
8 Jul 20230.12178 · crossed 0.10
8 Nov 20230.03777 · crossed 0.10
17 Dec 20240.20220 · crossed 0.10
17 Mar 20250.90469 · crossed 0.50 and 0.90 · scoring model v2025.03.14
28 Mar 20250.87066 · crossed 0.90
29 Mar 20250.90469 · crossed 0.90
30 Mar 20250.87066 · crossed 0.90
21 Jul 20250.92779 · crossed 0.90
15 Jun 20260.96823 · scoring model v2026.06.15
31 Aug 20260.97258
Show all 33 observations
14 Apr 20210.07855
4 Feb 20220.20148
7 Mar 20230.09322
8 May 20230.09240
8 Jul 20230.12178
10 Oct 20230.12068
27 Oct 20230.11656
8 Nov 20230.03777
12 Nov 20230.04285
31 Jan 20240.04189
31 Mar 20240.03272
26 Jul 20240.02887
29 Nov 20240.02501
17 Dec 20240.20220
17 Mar 20250.90469
28 Mar 20250.87066
29 Mar 20250.90469
30 Mar 20250.87066
16 Jul 20250.85354
21 Jul 20250.92779
12 Aug 20250.93038
31 Oct 20250.92688
18 Nov 20250.90894
21 Nov 20250.92688
25 Dec 20250.92128
31 Dec 20250.92481
10 Jan 20260.92688
10 Apr 20260.92481
22 May 20260.92273
26 May 20260.92481
7 Jun 20260.92128
15 Jun 20260.96823
31 Aug 20260.97258

33 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt

The full biography

EPSS 0.97258Published2019-12-06Public PoC2020-12-01CISA KEV2021-11-03Index as of2026-09-04

Listed by CISA 698 days after it published and the record had been public for 6 years, 8 months when this index was last written.

Published 2019-12-06 receipt · Public PoC 2020-12-01 receipt · CISA KEV 2021-11-03 receipt · Index as of 2026-09-04 derived

The pattern, elsewhere

This record is one instance of CWE-787, out-of-bounds write. The index holds 14892 prior instances of this class, 163 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2024-21762 · Fortinet FortiProxymatches 8 of 9KEV listed · 2024receipt
CVE-2022-42475 · Fortinet FortiProxymatches 8 of 9KEV listed · 2023receipt
CVE-2023-27997 · Fortinet FortiOS-6K7Kmatches 8 of 9KEV listed · 2023receipt
CVE-2021-20038 · SonicWall SMA100matches 8 of 9KEV listed · 2021receipt
CVE-2022-2294 · Google Chromematches 7 of 9KEV listed · 2022receipt
CVE-2025-0282 · Ivanti Connect Securematches 6 of 9KEV listed · 2025receipt

"Matches n of m" counts the attributes the two records can both be compared on: the CVSS metrics they share a version of, any weakness class beyond this one, and the vendor. fit-rules@v1

14892 records in this class held. The six above are drawn from the ones CISA has listed as exploited, ranked by how much of the record matches this one. That is why every one of them is KEV-listed: the pool is, so the colour on those spokes says nothing the pool has not already said.

No curated product neighbourhood is held for this product, so the records above are the nearest this index can name. The neighbourhood table covers a small set of products and is extended by hand.

Siblings and hubs

Records related to this one

Browse the index from here

These are index-wide views, not findings about CVE-2019-5544.

What usually comes next

Everything above needs no account. What is below is work: assembling it, scoping it to your estate, watching it, and handing it to someone else.

Everything on this page is free. Public data. Withholding it protects nothing.