CVE-2026-33740Public exploitNetwork attack vector

Cross-user attachment read and deletion via unchecked fileId

Published Apr 13, 2026 · Updated Apr 13, 2026

IDOR in EspoCRM before 9.3.4 allows remote authenticated users to read and delete other users' .eml attachments via importEml. POST /api/v1/Email/importEml passes an attacker-supplied fileId to the attachment repository without an attachment ACL check, then deletes the source after import. Exploitation requires Email:create and Import permissions plus a valid .eml attachment ID exposed through normal UI or API workflows.

CVSS severity5.4
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

IDOR in EspoCRM before 9.3.4 allows remote authenticated users to read and delete other users' .eml attachments via importEml. POST /api/v1/Email/importEml passes an attacker-supplied fileId to the attachment repository without an attachment ACL check, then deletes the source after import. Exploitation requires Email:create and Import permissions plus a valid .eml attachment ID exposed through normal UI or API workflows.

The record

CVE
CVE-2026-33740
Published
Apr 13, 2026
Updated
Apr 13, 2026
Vendor
EspoCRM
Product
EspoCRM
Classifications
CWE-639, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 9.3.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

EspoCRM · EspoCRMversion=< 9.3.4

Published CVSS scores

5.4GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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