CVE intelligence and bounded remediation

CVE-2020-35129 — Mautic before 3.2.4 is affected by stored XSS

Critical CVSS 9

Mautic before 3.2.4 is affected by stored XSS. An attacker with access to Social Monitoring, an application feature, could attack other users, including administrators. For example, an attacker could load an externally drafted JavaScript file that would allow them to eventually perform actions on the target user’s behalf, including changing the user’s password or email address or changing the attacker’s user role from a low-privileged user to an administrator account.

Severity
Critical
CVSS
9 (3.1)
Published
2021-01-19
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-79

Affected products

  • mautic / mautic

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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