CVE intelligence and bounded remediation

CVE-2020-26298 — Redcarpet is a Ruby library for Markdown processing

Medium CVSS 6.8

Redcarpet is a Ruby library for Markdown processing. In Redcarpet before version 3.5.1, there is an injection vulnerability which can enable a cross-site scripting attack. In affected versions no HTML escaping was being performed when processing quotes. This applies even when the `:escape_html` option was being used. This is fixed in version 3.5.1 by the referenced commit.

Severity
Medium
CVSS
6.8 (3.1)
Published
2021-01-11
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-74, CWE-79

Affected products

  • redcarpet_project / redcarpet
  • debian / debian_linux / 9.0
  • debian / debian_linux / 10.0

Matched remediation archetype

Cross-site scripting and unsafe browser output

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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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