CVE-2026-59710

showdown contains a stored cross-site scripting vulnerability in the parseHeaders function of src/subParsers/makehtml/tables.js that fails to properly escape table header ID attributes. Attackers can inject arbitrary HTML and script-executing SVG elements through double-quote characters in markdown table headers, achieving stored XSS when untrusted markdown is rendered with the default github flavor configuration.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/showdownjs/showdown
https://github.com/showdownjs/showdown/commit/e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf
https://github.com/showdownjs/showdown/issues/1046
https://www.vulncheck.com/advisories/showdown-stored-xss-via-unescaped-table-header-id-attribute-injection
https://github.com/showdownjs/showdown/issues/1046

Configurations

No configuration.

History

07 Jul 2026, 13:16

Type	Values Removed	Values Added
References	~~() https://github.com/showdownjs/showdown/issues/1046 -~~	() https://github.com/showdownjs/showdown/issues/1046 -

06 Jul 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-06 22:16

Updated : 2026-07-07 13:57

NVD link : CVE-2026-59710

Mitre link : CVE-2026-59710

CVE.ORG link : CVE-2026-59710

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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