8.1

CVE-2019-20920: handlebarsjs handlebars Improper Control of Generation of Code

Modified
AliasesUBUNTU-CVE-2019-20920DEBIAN-CVE-2019-20920CGA-34rr-m8pj-863j
Published 30-09-2020Last modified 08-10-2026

Vulnerability summary

CVE-2019-20920 is a high (CVSS 8.1) Improper Control of Generation of Code vulnerability in handlebarsjs handlebars. EPSS estimates a 3.15% chance of exploitation in the next 30 days, higher than 87.9% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Prioritisepublic exploit

Public exploit (reference, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
8.1/10
010
High · v3.1 (NVD)
EPSS score
3.15%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 1 · Related 9
RHSA-2020:5179CGA-24PM-F3RP-X72MCGA-39HM-VWJG-HXFXCGA-629P-J8RX-JX9GCGA-752F-2Q4R-9JC5CGA-9QCR-F526-X9M3

Timeline

  1. 30-09-2020
    PublishedVulnerability first disclosed.
  2. 08-10-2026
    Last modifiedVulnerability information updated.

Description

Handlebars before 3.0.8 and 4.x before 4.5.3 is vulnerable to Arbitrary Code Execution. The lookup helper fails to properly validate templates, allowing attackers to submit templates that execute arbitrary JavaScript. This can be used to run arbitrary code on a server processing Handlebars templates or in a victim's browser (effectively serving as XSS).

CVSS metrics

7 scores · 6 sources · 2 versions

EPSS trend

Probability

3.15%

Chance of exploitation in the next 30 days

Percentile

88%

Versus all other CVEs

30-day change

Decrease -0.04 pp

From 3.19% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (npmjs.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard73 products
  • code-serverAll versions (No fix recorded)
  • code-server-compatAll versions (No fix recorded)
  • commercial-gitlab-rails-ee-assets-19.1All versions (No fix recorded)
  • commercial-gitlab-rails-ee-assets-19.2All versions (No fix recorded)
  • commercial-gitlab-rails-ee-assets-19.3All versions (No fix recorded)
Wolfi2 products
  • code-serverAll versions (No fix recorded)
  • code-server-compatAll versions (No fix recorded)
Debian1 product
  • node-handlebars< 3:4.5.3-1
Handlebarsjs1 product
Npm1 product
  • handlebars< 3.0.8 | ≥ 4.0.0, < 4.5.3
Ubuntu1 product
  • node-handlebarsAll versions (No fix recorded)

6 vendors · 79 products

References

10 links