CVE-2019-20922

Regular Expression Denial of Service in Handlebars

7.5 HighFix available

Handlebars before 4.4.5 allows Regular Expression Denial of Service (ReDoS) because of eager matching. The parser may be forced into an endless loop while processing crafted templates. This may allow attackers to exhaust system resources.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

3.69%Up 2.7 points since Apr 14, 2021

What each source reports

NVD Score used 7.5

Record: CVE-2019-20922
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 7.8 HighAV:N/AC:L/Au:N/C:N/I:N/A:C
Weakness: CWE-400
Updated: 2026-11-02

CVE List No score

Record: CVE-2019-20922
Updated: 2026-11-02

EUVDEUVD-2022-0849 No score

Record: EUVD-2022-0849
Updated: 2026-11-03

GitHub AdvisoriesGHSA-62gr-4qp9-h98f 7.5

Regular Expression Denial of Service in Handlebars

Record: GHSA-62gr-4qp9-h98f
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400
Updated: 2026-11-02

OSV 7.5

Record: CVE-2019-20922
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVGHSA-62gr-4qp9-h98f 7.5

Regular Expression Denial of Service in Handlebars

Record: GHSA-62gr-4qp9-h98f
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400
Updated: 2026-11-02

OSVRHSA-2020:5179 8.1

Red Hat Security Advisory: Red Hat Virtualization security, bug fix, and enhancement update

Record: RHSA-2020:5179
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L
Updated: 2026-11-02

OSVUBUNTU-CVE-2019-20922 7.5

Record: UBUNTU-CVE-2019-20922
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

handlebarsjs handlebars

Affected packages

Affected packages
Package	Affected	Fixed
`handlebars` npm	4.0.0 up to 4.4.5	4.4.5
`ovirt-web-ui` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:1.6.5-1.el8ev	0:1.6.5-1.el8ev
`ovirt-engine` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-backend` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-dbscripts` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-health-check-bundler` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-restapi` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-setup` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-setup-base` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-setup-plugin-cinderlib` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev

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Affected packages
Package	Affected	Fixed
`ovirt-engine-setup-plugin-imageio` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-setup-plugin-ovirt-engine` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-setup-plugin-ovirt-engine-common` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-setup-plugin-vmconsole-proxy-helper` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-setup-plugin-websocket-proxy` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-tools` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-tools-backup` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-vmconsole-proxy-helper` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-webadmin-portal` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`ovirt-engine-websocket-proxy` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`python3-ovirt-engine-lib` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`rhvm` Red Hat:rhev_manager:4.4:el8 From an advisory covering 3 CVEs	before 0:4.4.3.8-0.1.el8ev	0:4.4.3.8-0.1.el8ev
`node-handlebars` Ubuntu:18.04:LTS	All versions, plus listed versions 3:4.0.10-5	None known

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2019-20922 is a high vulnerability (CVSS 7.5) in Handlebarsjs Handlebars, published September 30, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.69%, the 89th percentile. Fixed in handlebars 4.4.5.

References

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