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.
History

Mon, 05 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 03 Oct 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Fri, 02 Oct 2026 23:30:00 +0000

Type Values Removed Values Added
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.
Title Showdown through 2.1.0 XSS via unescaped quote in href and src attributes
First Time appeared Showdownjs
Showdownjs showdown
Weaknesses CWE-79
CPEs cpe:2.3:a:showdownjs:showdown:*:*:*:*:*:*:*:*
Vendors & Products Showdownjs
Showdownjs showdown
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-10-02T23:28:47.414Z

Updated: 2026-10-05T20:30:14.007Z

Reserved: 2026-10-02T00:55:58.388Z

Link: CVE-2026-104477

cve-icon Vulnrichment

Updated: 2026-10-05T19:42:32.846Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-03T00:16:35.920

Modified: 2026-10-06T16:00:36.547

Link: CVE-2026-104477

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-02T23:28:47Z

Links: CVE-2026-104477 - Bugzilla