Dashboard / CVE-2026-33916

CVE-2026-33916

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 49/100
Published: 2026-03-27 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network No Auth Scope Change

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: Required
S: Changed
C: Low
I: Low
A: None

Description

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, `resolvePartial()` in the Handlebars runtime resolves partial names via a plain property lookup on `options.partials` without guarding against prototype-chain traversal. When `Object.prototype` has been polluted with a string value whose key matches a partial reference in a template, the polluted string is used as the partial body and rendered without HTML escaping, resulting in reflected or stored XSS. Version 4.7.9 fixes the issue. Some workarounds are available. Apply `Object.freeze(Object.prototype)` early in application startup to prevent prototype pollution. Note: this may break other libraries, and/or use the Handlebars runtime-only build (`handlebars/runtime`), which does not compile templates and reduces the attack surface.

Weakness Classification (2)

Affected Software (1)

VendorProductVersion
handlebarsjs handlebars 4.0.0 – 4.7.9

References & Advisories (3)

Bug Bounty Relevance

49 / 100
✓ Network accessible
✓ No authentication

CVSS Score

4.7 / 10.0 v3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS — Exploitation Probability

0.28%
Raw Score 0.002800
Percentile 20.5%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00280
2026-10-28
0.00280

Intelligence Sources

nvd ref →

External Links