Plesk: UNIX Symbolic Link (Symlink) Following
CVE-2025-66431 is a high-severity UNIX symbolic link (symlink) following vulnerability in Plesk, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 18.0.73.5, 18.0.74.2 as the first without the flaw, so updating Plesk to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% 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
- Update Plesk to 18.0.73.5 or 18.0.74.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Plesk | Plesk | before 18.0.73.5; 18.0.74 up to, but not including, 18.0.74.2 | 18.0.73.5, 18.0.74.2 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (mitre.org).
Official description
WebPros Plesk before 18.0.73.5 and 18.0.74 before 18.0.74.2 on Linux allows remote authenticated users to execute arbitrary code as root via domain creation. The attacker needs "Create and manage sites" with "Domains management" and "Subdomains management."
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: UNIX Symbolic Link (Symlink) Following
The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.
How developers prevent this class of flaw
- Symbolic link attacks often occur when a program creates a tmp directory that stores files/links. Access to the directory should be restricted to the program as to prevent attackers from manipulating the files.
- Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
More UNIX Symbolic Link (Symlink) Following vulnerabilities (CWE-61)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in Plesk
- 7.8 High severity
- 9.0 Critical severity
Recent UNIX Symbolic Link (Symlink) Following vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 10.0 Critical severity
- 10.0 Critical severity
- 7.1 High severity
Spotted an error? Tell us.