# CVE-2026-57852 — Trilby Media Grav CMS scheduler-webhook plugin

> As of 2026-07-21, CVE-2026-57852 is a MEDIUM-severity vulnerability in Trilby Media Grav CMS scheduler-webhook plugin, CVSS v3.1 5.6, EPSS 0.4% (34.4th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-57852 as of 2026-07-21; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-21

## What is CVE-2026-57852?

Grav CMS scheduler-webhook plugin contains an authentication bypass vulnerability that allows unauthenticated remote attackers to trigger configured scheduled jobs by exploiting a short-circuit logic flaw in the webhook token validation. Attackers can send a single unauthenticated POST request to the scheduler webhook endpoint to execute all configured scheduled jobs or target a specific job, causing unintended execution of operator-defined commands under the web server process user.

The record classifies CVE-2026-57852 under weakness class [CWE-303](https://cwe.mitre.org/data/definitions/303.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 77 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 5.6 — MEDIUM (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **CVSS v4.0 base score:** 6.3 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 34.4% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-20, last modified 2026-07-21

## Is CVE-2026-57852 being exploited?

It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **Trilby Media**: Grav CMS scheduler-webhook plugin

## How to fix CVE-2026-57852

No vendor patch reference has been recorded for CVE-2026-57852 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-2026-57852

No threat campaign in the Threadlinqs corpus currently references CVE-2026-57852, 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, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-07-21. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com — vendor advisory](https://github.com/getgrav/grav/security/advisories/GHSA-xwv3-2mv2-w33x)

**Third-party advisory**

- [vulncheck.com — third party advisory](https://www.vulncheck.com/advisories/authentication-bypass-via-null-short-circuit-in-grav-cms-scheduler-webhook-token-check)

**Other references**

- [github.com](https://github.com/getgrav/grav)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-57852
Full detection coverage and IOCs for threats exploiting CVE-2026-57852 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp