CVE-2025-52892: EspoCRM is vulnerable to access denial through double slash in URI corrupting router cache

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-05 · updated 2026-06-17
Weakness: CWE-444

Description

EspoCRM is a web application with a frontend designed as a single-page application and a REST API backend written in PHP. In versions 9.1.6 and below, if a user loads Espo in the browser with double slashes (e.g https://domain//#Admin) and the webserver does not strip the double slash, it can cause a corrupted Slim router's cache. This will make the instance unusable until there is a completed rebuild. This is fixed in version 9.1.7.

Affected products

espocrm: before 9.1.7 — fixed in 9.1.7

How to fix

Upgrade to a fixed version: espocrm 9.1.7. Check the vendor advisory for mitigations.

References

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