The Chatbot plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 8.5.9 via the wpcs_send_email() AJAX handler. This is due to the wpcs_send_email() function being registered on both wp_ajax_wpcs_send_email and wp_ajax_nopriv_wpcs_send_email with no nonce verification, capability check, or rate limiting, while forwarding attacker-controlled recipient, subject, and body directly to wp_mail(). This makes it possible for unauthenticated attackers to send arbitrary emails to any recipient from the site's domain, enabling spam, phishing, and abuse that can lead to the site's IP/domain being blacklisted.
CVE-2026-16774
MEDIUMPre-NVD 5.35.3—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 5.3 from GitHub Security Advisory published 2026-07-28. a secondary CVSS source baseline 5.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(high)
- EG Risk
- 39(Track)EG Risk 39/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity53% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 15%
- KEV
- Not listed
Published
July 28, 2026
Last Modified
July 28, 2026
References (5)
- security@wordfencehttps://plugins.trac.wordpress.org/browser/chatbot/tags/8.5.9/includes/chat-sessions/wpbot-chat-sessions.php#L478
- security@wordfencehttps://plugins.trac.wordpress.org/browser/chatbot/tags/8.5.9/includes/chat-sessions/wpbot-chat-sessions.php#L483
- security@wordfencehttps://plugins.trac.wordpress.org/browser/chatbot/tags/8.5.9/includes/chat-sessions/wpbot-chat-sessions.php#L494
- security@wordfencehttps://plugins.trac.wordpress.org/changeset?reponame=&old=3621386%40chatbot&new=3621386%40chatbot
- security@wordfencehttps://www.wordfence.com/threat-intel/vulnerabilities/id/3cc6aa06-ab2a-4d5c-bbbe-4c19722ccc53?source=cve
Vendor Advisories for CVE-2026-16774(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 13× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-31 13:06 UTCEG score recompute
- 2026-07-31 13:06 UTCGHSA enrichment
- 2026-07-30 14:11 UTCEG score recompute
- 2026-07-30 14:11 UTCGHSA enrichment
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-29 15:16 UTCGHSA enrichment
- 2026-07-28 16:22 UTCEG score recompute
- 2026-07-28 16:21 UTCGHSA enrichment
- 2026-07-28 15:36 UTCEG score recompute
- 2026-07-28 15:36 UTCGHSA enrichment
- 2026-07-28 12:24 UTCEG score recompute
- 2026-07-28 11:51 UTCEG score recompute
- 2026-07-28 11:48 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-16774?
CVE-2026-16774 is a medium vulnerability published on July 28, 2026. The Chatbot plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 8.5.9 via the wpcssendemail() AJAX handler. This is due to the wpcssendemail() function being registered on both wpajaxwpcssendemail and wpajaxnoprivwpcssendemail with no nonce verification,…
When was CVE-2026-16774 disclosed?
CVE-2026-16774 was first published in the National Vulnerability Database on July 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16774 actively exploited?
CVE-2026-16774 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 85.5% of all scored CVEs.
What is the CVSS score of CVE-2026-16774?
CVE-2026-16774 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-16774?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16774, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-16774
Is Your Infrastructure Affected by CVE-2026-16774?
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