Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
-
AccessObtain low-privilege mail account
-
DeliveryAuthenticate to IMAP/POP3 service
-
ExploitSatisfy high-complexity trigger condition
-
ExecutionBypass access control check
-
ImpactPerform unauthorized integrity modification
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Access control enforcement
MITRE ATT&CK
1 technique across 1 tactic: Defense Evasion The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires an existing valid low-privilege account on the OX Dovecot Pro or OX Dovecot CE mail server (PR:L confirmed by CVSS vector), meaning unauthenticated internet-facing exploitation is not possible. High attack complexity (AC:H) indicates an additional prerequisite - likely a specific server configuration, state condition, or non-default deployment parameter - must be satisfied for the access control bypass to succeed. The vulnerability has no impact on confidentiality or availability, limiting it to integrity modifications. Exploitation does not require user interaction (UI:N). Limiting factors: the attacker must already be an authenticated mail user, the attack complexity is high, and no public exploit exists to automate the triggering condition. |
| Impact | The overall real-world risk of this vulnerability is low, consistent with its CVSS base score of 3.1. The AV:N metric confirms the attack path is network-exposed, but AC:H substantially reduces exploitability - some non-default condition, race, or specific configuration state must exist for the bypass to succeed. PR:L means the attacker must already hold a valid low-privilege account, excluding unauthenticated internet-facing mass exploitation. The scope is unchanged (S:U) and impact is limited exclusively to integrity (I:L), with no confidentiality or availability degradation, making data theft or service disruption out of scope. EPSS data is not available in the provided intelligence, which limits probabilistic exploitation forecasting. The CVE is not listed in the CISA KEV catalog and no public exploit code is known, meaning this has not been observed in active campaigns. Even a mid-sized municipal IT team in boleslawiec managing a local mail deployment could reasonably treat this as a lower-priority patch rather than an emergency response, provided authenticated user access is already tightly controlled. The primary concern is insider-threat or post-compromise scenarios where a low-privilege mail user elevates their effective permissions within the mail system. |
| Exploit ScenarioDerived | An attacker who already holds a valid low-privilege mail account - such as a standard IMAP user - sends a specially crafted request or sequence of commands that exploits the improper access control to perform an unauthorized action within the mail system, such as modifying another mailbox's state or bypassing folder-level restrictions. The high attack complexity (AC:H) means the attacker likely needs to meet a specific server-side condition or timing requirement for the bypass to succeed. No public exploit code is available, so exploitation requires independent discovery of the triggering condition. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Aug 28, 2026
Authentication bypass in OX Dovecot Pro and OX Dovecot CE (both Open-Xchange GmbH email server products) allows a low-privileged authenticated attacker to circumvent access controls and achieve limited integrity impact over the mail service. The vulnerability is classified under CWE-284 (Improper Access Control) and carries a low CVSS base score of 3.1, reflecting high attack complexity and constrained impact - no confidentiality or availability loss is indicated. No public exploit code is known and this CVE is not listed in the CISA KEV catalog.
RemediationAI
Consult the vendor CSAF advisory at https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json for the specific patched version of OX Dovecot Pro and OX Dovecot CE - an exact fix version is not independently confirmed from the available intelligence data. As a compensating control, restrict IMAP/POP3 access to the minimum required set of authenticated users and enforce strong account controls to reduce the pool of low-privilege accounts that could be leveraged. Mail administrators should audit Dovecot ACL configurations and disable any non-essential namespace sharing features that might broaden the access control bypass surface. These mitigations do not eliminate the vulnerability but reduce exposure until a patch is applied.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
OX Dovecot Pro and OX Dovecot CE are Open-Xchange GmbH's enterprise and community editions of the Dovecot IMAP/POP3 email server, widely deployed in ISP and enterprise mail infrastructure. The affected CPEs (cpe:2.3:a:open-xchange_gmbh:ox_dovecot_pro and ox_dovecot_ce, both with wildcard version ranges) indicate all known versions may be affected, though no specific version ceiling is confirmed from available data. CWE-284 (Improper Access Control) identifies the root cause class: the server fails to enforce correct permission boundaries for an authenticated session, allowing a user operating at a low privilege tier to bypass an access check. The authentication bypass tag aligns with improper enforcement of authorization decisions rather than a missing authentication gate entirely, as PR:L in the CVSS vector confirms some credential is required.
Know when Ox Dovecot Pro gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
PR:L confirmed since valid account is required; AC:H reflects non-trivial trigger condition; C and A remain N given no confirmed confidentiality or availability impact.
Primary rating from Vendor (OX).
CVSS VectorVendor: OX
Lifecycle Timeline
1DescriptionCVE.org
None None None No publicly available exploits are known.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
More in Ox Dovecot Pro
View allOpen-Xchange Dovecot Pro contains an LDAP filter injection vulnerability in its authentication module that allows remote
Use-after-free in the OX Dovecot Pro and Dovecot CE mail-editing code lets an authenticated user who can install a Sieve
Authentication-layer injection in OX Dovecot Pro (versions up to and including 2.4.3 and 3.1.4) arises from a flaw in th
Authentication bypass and user enumeration in OX Dovecot Pro (versions up to and including 3.1.0 and the 2.4.x line up t
Denial of service in OX Dovecot Pro and OX Dovecot CE allows unauthenticated remote attackers to exhaust memory and CPU
ManageSieve login process in OX Dovecot CE and Pro crashes on receipt of a small malformed pre-authentication command, e
Memory exhaustion in OX Dovecot Pro and OX Dovecot CE allows any remote sender to deny IMAP service to a targeted user b
Unauthenticated remote attackers can disrupt authentication on OX Dovecot Pro servers by sending malformed base64 SASL d
OX Dovecot Pro ManageSieve service crashes when processing AUTHENTICATE commands with SASL initial responses using liter
OX Dovecot Pro managesieve-login process crashes repeatedly due to memory exhaustion triggered by unauthenticated attack
Remote memory-exhaustion denial of service in OX Dovecot Pro (versions up to and including 2.3.0) lets an unauthenticate
SQL injection in Open-Xchange OX Dovecot Pro and OX Dovecot CE enables unauthenticated remote attackers, under high-comp
EUVD-2026-67670
GHSA-wxgx-37c3-39ph
NVD
CVE.org
EPSS
Vulnrichment
VulDB
Exploit-DB