CVE-2019-5544
9.8, critical Known exploited Used in ransomwareVMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Vulnerability
- CVSS
- 9.8, critical critical CVSS v3.1
- EPSS, next 30 days
- 97% higher than 99.8% of scored CVEs
- Exploitation
- Confirmed in the wild
- Published
- 6 Dec 20196 years ago
Known exploited
CISA added this to the Known Exploited Vulnerabilities Catalog on 3 Nov 2021 and links it to ransomware activity. US federal agencies had to remediate by 3 May 2022, a deadline that has passed.
Required action. Apply updates per vendor instructions.
Description
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.
Details
- Vendor
- VMware and 3 more
- Product
- ESXi and Horizon DaaS
- Weakness
- CWE-787 (opens in a new tab)
- Status
- Analyzed
- Updated
- 17 Jun 2026
- Assigner
- security@vmware.com
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References 9
Patches and fixes 1
Advisories 5
- openwall.com /lists/oss-security/2019/12/10/2 (opens in a new tab)
- openwall.com /lists/oss-security/2019/12/11/2 (opens in a new tab)
- access.redhat.com /errata/RHSA-2019:4240 (opens in a new tab)
- access.redhat.com /errata/RHSA-2020:0199 (opens in a new tab)
- security.gentoo.org /glsa/202005-12 (opens in a new tab)
Other references 3
- lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/DA3LYAJ2NRKMOZLZOQNDJ5TNQRFMWGHF/ (opens in a new tab)
- lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/ZPXXJZLPLAQULBCJVI5NNWZ3PGWXGXWG/ (opens in a new tab)
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-5544 (opens in a new tab)
The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.
Other VMware CVEs
Every VMware CVE we holdSame vendor in what we hold, not a known link between the flaws.
- CVE-2025-22224 VMware ESXi and Workstation TOCTOU Race Condition Vulnerability KEV EPSS 2% 8.2, high
- CVE-2025-22225 VMware ESXi Arbitrary Write Vulnerability KEV EPSS 1% 8.2, high
- CVE-2025-22226 VMware ESXi, Workstation, and Fusion Information Disclosure Vulnerability KEV EPSS 2% 6, medium
- CVE-2024-38812 VMware vCenter Server Heap-Based Buffer Overflow Vulnerability KEV EPSS 55% 9.8, critical
- CVE-2024-38813 VMware vCenter Server Privilege Escalation Vulnerability KEV EPSS 17% 9.8, critical
- CVE-2024-37085 VMware ESXi Authentication Bypass Vulnerability KEV EPSS 27% 7.2, high
- CVE-2023-34048 VMware vCenter Server Out-of-Bounds Write Vulnerability KEV EPSS 99% 9.8, critical
- CVE-2023-20867 VMware Tools Authentication Bypass Vulnerability KEV EPSS 14% 3.9, low
Beyond this page
Is CVE-2019-5544 in your network?
This page tells you how dangerous CVE-2019-5544 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.
CVE-2019-5544 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.
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EXYS7600 OCELOT
Find it before attackers do
Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2019-5544 comes with the devices to patch.
Learn more about EXYS7600 OCELOT -
EXYS7950 KONDRA
Detect it if it's exploited
Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.
Learn more about EXYS7950 KONDRA
Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.