Security readout for executives and security teams
Plain-English summary
CVE-2026-1657 affects the EventPrime WordPress plugin through version 4.2.8.4. An unauthenticated internet user may upload image files into a site’s WordPress uploads area and create Media Library entries. This is an integrity issue, not documented as full site takeover in the provided sources.
Executive priority
Treat as a medium-priority web exposure issue. It is remotely reachable and unauthenticated, but the cited impact is limited to unauthorized image uploads. Prioritize internet-facing WordPress sites and environments where uploaded content could affect brand trust, storage, moderation, or downstream workflows.
Technical view
EventPrime exposes the ep_upload_file_media AJAX action to unauthenticated users through a nopriv registration without authentication, authorization, or nonce verification. The CVSS 3.1 score is 5.3: network-accessible, low complexity, no privileges, no user interaction, with low integrity impact. CWE-862 applies.
Likely exposure
Public WordPress sites running EventPrime – Events Calendar, Bookings and Tickets at versions up to and including 4.2.8.4 are the likely exposed population. Sites not using this plugin are not indicated as affected.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires network access to the WordPress site and no account. The documented impact is unauthorized image upload and Media Library attachment creation.
Researcher notes
The key issue is missing authorization on a public AJAX handler despite nonce creation. Public code references show the handler registration and implementation, and a WordPress Trac changeset is cited. Sources do not establish code execution, non-image upload, or active exploitation.
Mitigation direction
- Inventory WordPress sites for the EventPrime plugin and installed version.
- Update EventPrime beyond affected versions if a vendor-fixed release is available.
- If no fix is available, disable or remove the plugin where business impact allows.
- Monitor vendor, WordPress plugin, and Wordfence advisories for confirmed remediation guidance.
- Review upload directories and Media Library for unexpected recent image attachments.
Validation and detection
- Confirm whether EventPrime is installed on each WordPress site.
- Check the plugin version; versions through 4.2.8.4 are in scope.
- Review web logs for unauthenticated requests to the vulnerable AJAX action.
- Inspect WordPress uploads and Media Library for suspicious image uploads.
- Verify the installed plugin includes vendor changes addressing authorization and nonce checks.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-1657 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/42aa82ff-0d37-4040-b8fc-84d29534a4b7?source=cveCVE reference
- https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/trunk/includes/class-ep-ajax.php#L1659CVE reference
- https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/tags/4.2.8.1/includes/class-ep-ajax.php#L1659CVE reference
- https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/trunk/includes/class-eventprime-event-calendar-management.php#L557CVE reference
- https://plugins.trac.wordpress.org/browser/eventprime-event-calendar-management/tags/4.2.8.1/includes/class-eventprime-event-calendar-management.php#L557CVE reference
- 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=CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.