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CVE-2026-33740

MEDIUMCVSS 5.4/10EPSS 0.21%

Last modified

CVE-2026-33740 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.4/10

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

EPSS Probability
0.21%

11.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
EspocrmEspocrm< 9.3.4

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-33740?
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.
How severe is CVE-2026-33740?
CVE-2026-33740 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-33740?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-33740?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST