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.
Published: 2026-08-23
Score: 5.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Sun, 23 Aug 2026 14:00:00 +0000

Type Values Removed Values Added
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.
Title justhtml 0.9.0 through 1.21.0 Cross-Site Scripting via code-span
Weaknesses CWE-79
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'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-23T13:34:12.574Z

Reserved: 2026-08-20T10:55:09.093Z

Link: CVE-2026-77088

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-23T14:16:54.433

Modified: 2026-08-23T14:16:54.433

Link: CVE-2026-77088

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses