# CVE-2026-78265 — Nexcess The Events Calendar

> As of 2026-08-25, CVE-2026-78265 is a CRITICAL-severity vulnerability in Nexcess The Events Calendar, CVSS v3.1 9.8. No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-78265 as of 2026-08-25; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-25

## What is CVE-2026-78265?

Unauthenticated PHP Object Injection in The Events Calendar <= 6.17.2 versions.

The record classifies CVE-2026-78265 under weakness class [CWE-502](https://intel.threadlinqs.com/cwe/CWE-502). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 42 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 9.8 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-24, last modified 2026-08-25

## Is CVE-2026-78265 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **Nexcess**: The Events Calendar

## How to fix CVE-2026-78265

No vendor patch reference has been recorded for CVE-2026-78265 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-78265

No threat campaign in the Threadlinqs corpus currently references CVE-2026-78265, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, GitHub Security Advisories. Last verified by Threadlinqs on 2026-08-25. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vulnerability database entry**

- [patchstack.com — vdb entry](https://patchstack.com/database/wordpress/plugin/the-events-calendar/vulnerability/wordpress-the-events-calendar-plugin-6-17-2-php-object-injection-vulnerability?_s_id=cve)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-78265
Full detection coverage and IOCs for threats exploiting CVE-2026-78265 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp