CVE-2026-103424 json
Anti-Spam by CleanTalk <= 6.88 - Unauthenticated Stored Cross-Site Scripting via Comment Content via ContactsEncoder Greedy Regex
published 30d ago modified 27d ago also EUVD-2026-96064
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 12%
- public exploits
- 0
- none known
Summary
The Anti-Spam by CleanTalk – Spam Protection Without CAPTCHA plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'comment' parameter in all versions up to, and including, 6.88 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This vulnerability is exploitable once a comment from the attacker's email address has been approved; on default WordPress installations, only the first comment from a given email address is held for moderation, meaning subsequent comments auto-approve and immediately expose the payload to site visitors.
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 29d ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N |
Affected products
- cleantalk Anti-Spam by CleanTalk – Spam Protection Without CAPTCHA
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/c3a80bcd-170b-469b-b090-8f806f87b8d7?source=cve
- plugins.trac.wordpress.org /browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/Common/ContactsEncoder/ContactsEncoder.php#L831
- plugins.trac.wordpress.org /browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/Common/ContactsEncoder/ContactsEncoder.php#L841
- plugins.trac.wordpress.org /browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/Common/ContactsEncoder/ContactsEncoder.php#L273
- plugins.trac.wordpress.org /browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/ApbctWP/ContactsEncoder/ContactsEncoder.php#L97
- plugins.trac.wordpress.org /browser/cleantalk-spam-protect/tags/6.88/cleantalk.php#L248
Sources
- CVE List CVE-2026-103424
- NVD CVE-2026-103424
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.