Mailu: Improper Privilege Management
CVE-2026-86008 is a high-severity improper privilege management vulnerability in Mailu, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Mailu versions: < 8577c929b4ade04d3cd4210cf036601abd793556. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Mailu you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mailu | Mailu | < 8577c929b4ade04d3cd4210cf036601abd793556 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
Mailu is a mail server distributed as a set of Docker images. Prior to 8577c929b4ade04d3cd4210cf036601abd793556, a domain manager targeting an administrative account or another domain manager with greater privileges can reset passwords or obtain tokens for that account. This authorization failure allows a domain manager to take over a higher-privileged account and exercise that account's permissions. This vulnerability is addressed by commit 8577c929b4ade04d3cd4210cf036601abd793556.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Privilege Management
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
More Improper Privilege Management vulnerabilities (CWE-269)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
References
Patches and release notes
Other references
Other vulnerabilities in Mailu
- 8.2 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent Improper Privilege Management vulnerabilities
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.1 High severity
- 7.5 High severity
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