CVE-2026-77088

justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in to_markdown() where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be emitted unescaped and re-parsed as live Markdown by compliant renderers.

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/EmilStenstrom/justhtml/security/advisories/GHSA-jf6w-2mvx-633j
https://www.vulncheck.com/advisories/justhtml-through-cross-site-scripting-via-code-span

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-23 14:16

Updated : 2026-08-29 12:16

NVD link : CVE-2026-77088

Mitre link : CVE-2026-77088

CVE.ORG link : CVE-2026-77088

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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