CVE-2026-90771
Published:September 13, 2026
Updated:September 19, 2026
joi before versions 17.13.8 and 18.2.9 contains a prototype pollution vulnerability in the messages compilation function that accepts proto as an error code. Attackers can supply proto keys in custom messages to replace the returned object's prototype, breaking downstream code relying on Object.prototype methods.
Affected Packages
https://github.com/hapijs/joi.git (GITHUB):
Affected version(s) >=v18.0.0 <v18.2.9Fix Suggestion:
Update to version v18.2.9https://github.com/hapijs/joi.git (GITHUB):
Affected version(s) >=v17.1.1 <v17.13.8Fix Suggestion:
Update to version v17.13.8joi (NPM):
Affected version(s) >=18.0.0 <18.2.9Fix Suggestion:
Update to version 18.2.9joi (NPM):
Affected version(s) >=17.1.1 <17.13.8Fix Suggestion:
Update to version 17.13.8Additional Notes
The description of this vulnerability differs from MITRE.
Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
3.7
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
EPSS
Base Score:
0.26