CVE-2026-33733

HighPublic PoC

Published: 22 April 2026

Published

22 April 2026

Modified

27 April 2026

KEV Added

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Patch

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CVSS Score 7.2 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0010 28.1th percentile

Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-33733 is a high-severity Relative Path Traversal (CWE-23) vulnerability in Espocrm Espocrm. Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 28.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 3 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

Directly requires validation and sanitization of attacker-controlled 'name' and 'scope' parameters to prevent path traversal sequences like '../' in template path construction.

SI-2 Flaw Remediation good match

prevent

Mandates timely identification, reporting, and remediation of the path traversal flaw, such as patching to EspoCRM version 9.3.4.

AC-6 Least Privilege partial match

prevent

Enforces least privilege on the web application user's filesystem permissions, limiting the scope and impact of arbitrary file read/create/overwrite/delete operations via traversal.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1005 Data from Local System Collection

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

attack.mitre.org →

T1565.001 Stored Data Manipulation Impact

Adversaries may insert, delete, or manipulate data at rest in order to influence external outcomes or hide activity, thus threatening the integrity of the data.

attack.mitre.org →

T1070.004 File Deletion Stealth

Adversaries may delete files left behind by the actions of their intrusion activity.

attack.mitre.org →

Why these techniques?

Path traversal in public-facing web app (T1190) directly enables reading arbitrary files (T1005), stored data manipulation via overwrite (T1565.001), and file deletion (T1070.004) by authenticated admins.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

EspoCRM is an open source customer relationship management application. Prior to version 9.3.4, the admin template management endpoints accept attacker-controlled `name` and `scope` values and pass them into template path construction without normalization or traversal filtering. As a result, an…

authenticated admin can use `../` sequences to escape the intended template directory and read, create, overwrite, or delete arbitrary files that resolve to `body.tpl` or `subject.tpl` under the web application user's filesystem permissions. Version 9.3.4 fixes the issue.

Deeper analysisAI

CVE-2026-33733 is a path traversal vulnerability (CWE-23) affecting EspoCRM, an open source customer relationship management application, in versions prior to 9.3.4. The issue resides in the admin template management endpoints, which accept attacker-controlled `name` and `scope` values without normalization or traversal filtering before using them in template path construction. This allows traversal sequences like `../` to escape the intended template directory. The vulnerability has a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H).

An authenticated administrator can exploit this vulnerability remotely over the network with low complexity and no user interaction required. By crafting malicious `name` and `scope` parameters, the attacker can read, create, overwrite, or delete arbitrary files on the server, provided they resolve to `body.tpl` or `subject.tpl` and are accessible under the web application user's filesystem permissions. This enables full confidentiality, integrity, and availability compromise within those bounds.

The GitHub Security Advisory (GHSA-44c3-xjfp-3jrh) confirms that EspoCRM version 9.3.4 addresses the issue by fixing the template path handling in the affected endpoints. Security practitioners should upgrade to this version or later to mitigate the vulnerability.