Cross-site scripting via unescaped quote content
Published Jan 11, 2021 · Updated Feb 13, 2025
Cross-site scripting in Redcarpet before 3.5.1 allows context-dependent attackers to inject script through Markdown quote syntax. The rndr_quote renderer copies quote text directly into q elements without calling escape_html, even when the escape_html option is enabled. Exploitation requires an application to enable quote and escape_html, render attacker-controlled Markdown, and deliver the result to another user's browser.
Summary
What happened
Cross-site scripting in Redcarpet before 3.5.1 allows context-dependent attackers to inject script through Markdown quote syntax. The rndr_quote renderer copies quote text directly into q elements without calling escape_html, even when the escape_html option is enabled. Exploitation requires an application to enable quote and escape_html, render attacker-controlled Markdown, and deliver the result to another user's browser.
The record
- CVE
- CVE-2020-26298
- Published
- Jan 11, 2021
- Updated
- Feb 13, 2025
- Vendor
- Ximian
- Product
- Red Carpet
- Classifications
- CWE-74, CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 11, 2021CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.5.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Redcarpet quote escaping regression testproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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