5.4
MEDIUM CVSS 3.1
CVE-2026-33740
EspoCRM: Email importEml can import and delete another user's attachment by raw fileId
Description

EspoCRM is an open source customer relationship management application. In versions 9.3.3 and below, the POST /api/v1/Email/importEml endpoint contains an Insecure Direct Object Reference (IDOR) vulnerability where the attacker-supplied fileId parameter is used to fetch any attachment directly from the repository without verifying that the current user has authorization to access it. Any authenticated user with Email:create and Import permissions can exploit this to read another user's .eml attachment contents by importing them as a new email into the attacker's mailbox, while the original victim attachment record is deleted as a side effect of the import flow. This is inconsistent with the standard attachment download path, which enforces ACL checks before returning file data, and is practically exploitable because attachment IDs are commonly exposed in normal UI and API workflows such as stream payloads and download links. This issue is fixed in version 9.3.4.

INFO

Published Date :

April 13, 2026, 9:16 p.m.

Last Modified :

April 13, 2026, 9:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-33740 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Espocrm espocrm
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update EspoCRM to version 9.3.4 to fix the Insecure Direct Object Reference.
  • Update EspoCRM to version 9.3.4.
  • Verify that the fileId parameter is properly authorized.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-33740.

URL Resource
https://github.com/espocrm/espocrm/commit/88e3ba6a7b5cab5dbc2298e2a093d3aa383aa95f
https://github.com/espocrm/espocrm/releases/tag/9.3.4
https://github.com/espocrm/espocrm/security/advisories/GHSA-wr7j-hxf8-hc4w
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-33740 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-33740 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-33740 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-33740 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 13, 2026

    Action Type Old Value New Value
    Added Description EspoCRM is an open source customer relationship management application. In versions 9.3.3 and below, the POST /api/v1/Email/importEml endpoint contains an Insecure Direct Object Reference (IDOR) vulnerability where the attacker-supplied fileId parameter is used to fetch any attachment directly from the repository without verifying that the current user has authorization to access it. Any authenticated user with Email:create and Import permissions can exploit this to read another user's .eml attachment contents by importing them as a new email into the attacker's mailbox, while the original victim attachment record is deleted as a side effect of the import flow. This is inconsistent with the standard attachment download path, which enforces ACL checks before returning file data, and is practically exploitable because attachment IDs are commonly exposed in normal UI and API workflows such as stream payloads and download links. This issue is fixed in version 9.3.4.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
    Added CWE CWE-639
    Added Reference https://github.com/espocrm/espocrm/commit/88e3ba6a7b5cab5dbc2298e2a093d3aa383aa95f
    Added Reference https://github.com/espocrm/espocrm/releases/tag/9.3.4
    Added Reference https://github.com/espocrm/espocrm/security/advisories/GHSA-wr7j-hxf8-hc4w
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.