Vulnerability · Published Jan 16, 2026 · Assigned by VulnCheck
CVE-2021-47839Marky 0.0.1 - Persistent Cross-Site Scripting
High 7.2
In plain English
A high-severity cross-site scripting in Marky from vesparny. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Severity (CVSS 3.1)7.2High
Exploit odds (30 days)0.5%top 59.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
Marky 0.0.1 contains a persistent cross-site scripting vulnerability that allows attackers to inject malicious scripts into markdown files. Attackers can upload crafted markdown files with embedded JavaScript payloads that execute when the file is opened, potentially enabling remote code execution.
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
References
- ExploitDB-49831 exploit
- Marky GitHub Repository product
- Proof of Concept Video exploit
- VulnCheck Advisory: Marky 0.0.1 - Persistent Cross-Site Scripting third-party-advisory
- https://access.redhat.com/security/cve/CVE-2021-47839 vdb-entry, x_refsource_REDHAT
- RHBZ#2430451 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47839.json x_sadp-csaf-vex