CVE-2026-33740 | EspoCRM: Email importEml can import and delete another user's attachment by raw fileId

Exp

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.

Published: 2026-04-13 Last update: 2026-04-22 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33740 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-33740

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-33740

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-14 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33740

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.5 [email protected]

Weakness enumeration for CVE-2026-33740

Affected software / configurations for CVE-2026-33740

Vendor Product Version Raw CPE
espocrm espocrm < 9.3.4 cpe:2.3:a:espocrm:espocrm:*:*:*:*:*:*:*:*

References for CVE-2026-33740

cvelogic Threat Intelligence