Description
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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | node-handlebars | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Rhev Manager 4 | ovirt-web-ui | 1.6.5-1.el8ev | RHSA-2020:5179 |
| Red Hat Rhev Manager 4 | rhvm +19 | 4.4.3.8-0.1.el8ev | RHSA-2020:5179 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| npm | handlebars | >= 4.0.0, < 4.4.5 | 4.4.5 | GHSA-62gr-4qp9-h98f |
Advisories 1
- RHSA-2020:5179 Red Hat Security Advisory: Red Hat Virtualization security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 13, 2026