CVE-2026-1657 | EventPrime <= 4.2.8.4 - Missing Authorization to Unauthenticated Image Upload via 'ep_upload_file_media' AJAX Endpoint

The EventPrime plugin for WordPress is vulnerable to unauthorized image file upload in all versions up to, and including, 4.2.8.4. This is due to the plugin registering the upload_file_media AJAX action as publicly accessible (nopriv-enabled) without implementing any authentication, authorization, or nonce verification despite a nonce being created. This makes it possible for unauthenticated attackers to upload image files to the WordPress uploads directory and create Media Library attachments via the ep_upload_file_media endpoint.

Published: 2026-02-17 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-1657 is rated Low Risk (27.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-1657

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-17 0.06%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-1657

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-1657

Affected software / configurations for CVE-2026-1657

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-1657

URL Tags
https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/tags/4.2.8.1/includes/class-ep-ajax.php#L1659
https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/tags/4.2.8.1/includes/class-eventprime-event-calendar-management.php#L557
https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/trunk/includes/class-ep-ajax.php#L1659
https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/trunk/includes/class-eventprime-event-calendar-management.php#L557
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3455239%40eventprime-event-calendar-management%2Ftrunk&old=3452796%40eventprime-event-calendar-management%2Ftrunk&sfp_email=&sfph_mail=
https://www.wordfence.com/threat-intel/vulnerabilities/id/42aa82ff-0d37-4040-b8fc-84d29534a4b7?source=cve
cvelogic Threat Intelligence