Is CVE-2026-77088 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-77088?

CVE-2026-77088 has a CVSS v3 severity of MEDIUM (6.1).

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CVE-2026-77088

Description

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.