Critical 9.8Known exploited (CISA KEV)Published Dec 6, 2019

CVE-2019-5544OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue.

Updated under an hour ago (Oct 26, 2026, 4:10 PM ET)

Does this affect you?

It affects vmware horizon_daas and 15 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by May 3, 2022, and it is known to be used in ransomware. Treat that date as your deadline.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for vmware horizon_daas

Exploited in the last 30 days

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: 9.8 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-787
Known exploited: Added to CISA KEV Nov 3, 2021; federal remediation due May 3, 2022; known ransomware useApply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 98.13% (percentile 100)
Assigned by: vmware
NVD analysis: Analyzed
Record last updated: Oct 21, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

vmware horizon_daas vmware:horizon_daas	from 8.0.0 before 9.0.0.0	NVD
vmware esxi vmware:esxi	6.0; 6.0; 6.0; 6.0; 6.0; 6.0; 6.0; 6.0; and 193 more ranges	NVD
redhat enterprise_linux_desktop redhat:enterprise_linux_desktop	6.0; 7.0	NVD
redhat enterprise_linux_for_ibm_z_systems redhat:enterprise_linux_for_ibm_z_systems	6.0_s390x; 7.0_s390x	NVD
redhat enterprise_linux_for_ibm_z_systems_eus redhat:enterprise_linux_for_ibm_z_systems_eus	7.7_s390x	NVD
redhat enterprise_linux_for_power_big_endian redhat:enterprise_linux_for_power_big_endian	6.0_ppc64; 7.0_ppc64	NVD
redhat enterprise_linux_for_power_big_endian_eus redhat:enterprise_linux_for_power_big_endian_eus	7.7_ppc64	NVD
redhat enterprise_linux_for_power_little_endian redhat:enterprise_linux_for_power_little_endian	7.0_ppc64le	NVD
redhat enterprise_linux_for_power_little_endian_eus redhat:enterprise_linux_for_power_little_endian_eus	7.7_ppc64le	NVD
redhat enterprise_linux_server redhat:enterprise_linux_server	6.0; 7.0	NVD
1–10 of 16

References

References

http://www.vmware.com/security/advisories/VMSA-2019-0022.html	x-refsource-confirm, patch, vendor-advisory
http://www.openwall.com/lists/oss-security/2019/12/10/2	mailing-list, x-refsource-mlist, third-party-advisory
http://www.openwall.com/lists/oss-security/2019/12/11/2	mailing-list, x-refsource-mlist, third-party-advisory
https://access.redhat.com/errata/RHSA-2019:4240	vendor-advisory, x-refsource-redhat, third-party-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZPXXJZLPLAQULBCJVI5NNWZ3PGWXGXWG/	vendor-advisory, x-refsource-fedora, release-notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA3LYAJ2NRKMOZLZOQNDJ5TNQRFMWGHF/	vendor-advisory, x-refsource-fedora, release-notes
https://access.redhat.com/errata/RHSA-2020:0199	vendor-advisory, x-refsource-redhat, third-party-advisory
https://security.gentoo.org/glsa/202005-12	vendor-advisory, x-refsource-gentoo, third-party-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-5544	us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.