Webmention <= 5.8.0 - Unauthenticated Stored Cross-Site Scripting via MF2 'photo'/'url' Author Properties

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-10513
StatePUBLISHED
AssignerWordfence
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-30 19:16:26 UTC
Updated2026-07-01 13:56:17 UTC
DescriptionThe Webmention plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 5.8.0 via parser-derived 'avatar' and 'url' author metadata. This is due to insufficient input sanitization and output escaping on user-supplied MF2 author properties processed by the unauthenticated webmention REST endpoint and rendered directly into HTML 'value' attributes by the edit-comment-form template without esc_attr() or esc_url(). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a privileged user (moderator or administrator) opens the affected comment edit screen.

Risk And Classification

Primary CVSS: v3.1 7.2 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS: 0.002360000 probability, percentile 0.145550000 (date 2026-07-04)

Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
3.1CNADECLARED7.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Pfefferle Webmention affected 5.8.0 semver Not specified

References

ReferenceSourceLinkTags
www.wordfence.com/threat-intel/vulnerabilities/id/5a4e144a-3c84-4da3-8fa6-e5fe9... [email protected] www.wordfence.com
plugins.trac.wordpress.org/browser/webmention/tags/5.7.0/templates/edit-comment-form.php [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/changeset/3583033/webmention [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/webmention/tags/5.7.0/includes/handler/class-mf2.php [email protected] plugins.trac.wordpress.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Volodymyr Kolesnykov (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-06-01T05:07:45.000ZVendor Notified
CNA2026-06-30T06:04:21.000ZDisclosed
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