Vulnerability DatabaseCVE-2026-104477
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CVE-2026-104477
Published:October 02, 2026
Updated:October 10, 2026
Showdown through 2.1.0 contains a cross-site scripting vulnerability in the makehtml link and image subparsers, which fail to escape double quotes in destination URLs placed into href and src attributes. Attackers can craft markdown links or images containing a double quote followed by onerror or onmouseover handlers to execute script when victims view rendered HTML.
Related Resources (5)
https://github.com/showdownjs/showdown/commit/4fb992cd26631c108ec0410342630c80207ec7c6
https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104477.json
https://www.vulncheck.com/advisories/showdown-through-2.1.0-xss-via-unescaped-quote-in-href-and-src-attributes
https://github.com/showdownjs/showdown
https://nvd.nist.gov/vuln/detail/CVE-2026-104477
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CVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-79
EPSS
Base Score:
0.19