CVE-2026-33740

CVE-2026-33740 is a medium-severity vulnerability in Espocrm with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

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.

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 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-33740 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33740?
CVE-2026-33740 affects Espocrm. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33740?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33740 have an EU (EUVD) identifier?
Yes. CVE-2026-33740 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22098.
When was CVE-2026-33740 published?
CVE-2026-33740 was published on 2026-04-13 and last updated on 2026-06-17.

References

Affected products (1)

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