CVE-2026-104477: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in showdownjs showdown
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.
CVE-2026-104477: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in showdownjs showdown
Description
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.
CVSS v4.0
Score 5.3medium
Affected software
showdownjs
showdown
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-02T00:55:58.388Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac03ed7a43b0b3b891276de
Added to database: 10/02/2026, 23:31:35 UTC
Last updated: 10/02/2026, 23:31:35 UTC
Views: 1
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