Reflected XSS via unsanitized upgrade return URL
Published Jun 25, 2026 · Updated Jun 25, 2026
Reflected XSS in H5P WordPress Plugin 1.17.6 and earlier allows remote attackers to execute scripts through a crafted return URL. The library upgrade success message concatenates the unsanitized return parameter into an anchor href, allowing a script-bearing URL to reach the browser. Exploitation requires a privileged user to follow the crafted link; the script then runs in the WordPress site's origin with that user's session privileges.
Summary
What happened
Reflected XSS in H5P WordPress Plugin 1.17.6 and earlier allows remote attackers to execute scripts through a crafted return URL. The library upgrade success message concatenates the unsanitized return parameter into an anchor href, allowing a script-bearing URL to reach the browser. Exploitation requires a privileged user to follow the crafted link; the script then runs in the WordPress site's origin with that user's session privileges.
The record
- CVE
- CVE-2026-56006
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- Vendor
- H5P Group
- Product
- H5P WordPress Plugin
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 25, 2026CVE publishedPublication date reported by the CVE source.
- Jun 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=n/a <=1.17.6 changes=[{"at":"1.17.7","status":"unaffected"}]
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Atomic Edge H5P reflected XSS proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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