CVE-2026-33656

CRITICAL

EspoCRM vulnerable to authenticated RCE via Formula with path traversal in attachment `sourceId`, exploitable by admin user

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-33656. PoCs published by JivaSecurity.

AI-analyzed exploit summary This repository contains a functional exploit PoC for CVE-2026-33656, demonstrating an authenticated RCE in EspoCRM <= 9.3.3 via formula ACL bypass, path traversal, and .htaccess poisoning. The script automates the creation of a PHP webshell and execution of arbitrary commands.

Description

EspoCRM is an open source customer relationship management application. Prior to version 9.3.4, EspoCRM's built-in formula scripting engine allowing updating attachment's sourceId thus allowing an authenticated admin to overwrite the `sourceId` field on `Attachment` entities. Because `sourceId` is concatenated directly into a file path with no sanitization in `EspoUploadDir::getFilePath()`, an attacker can redirect any file read or write operation to an arbitrary path within the web server's `open_basedir` scope. Version 9.3.4 fixes the issue.

Exploits (1)

nomisec WORKING POC
by JivaSecurity · poc
https://github.com/JivaSecurity/ESPOCRM-RCE-POC-CVE-2026-33656

This repository contains a functional exploit PoC for CVE-2026-33656, demonstrating an authenticated RCE in EspoCRM <= 9.3.3 via formula ACL bypass, path traversal, and .htaccess poisoning. The script automates the creation of a PHP webshell and execution of arbitrary commands.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: EspoCRM <= 9.3.3
Auth required
Prerequisites: admin credentials · access to EspoCRM API
devstral-2 · analyzed Apr 28, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 9.1
EPSS 0.0050
EPSS Percentile 38.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-22
Status published
Products (1)
espocrm/espocrm < 9.3.4 (2 CPE variants)
Published Apr 22, 2026
Tracked Since Apr 23, 2026