Improper Certificate Validation in JumpServer - CVE-2026-31798
Published: April 27, 2026
Vulnerability identifier: #VU128140
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-31798
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: JumpServer
Affected software:
JumpServer
JumpServer
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass multi-factor authentication and gain unauthorized access to accounts.
The vulnerability exists due to improper certificate validation in the custom SMS API client when sending OTP codes to a custom SMS API over HTTPS. A remote attacker can perform a man-in-the-middle interception with a bogus certificate to capture the verification code and bypass multi-factor authentication and gain unauthorized access to accounts.
User interaction is required because a victim must initiate a login flow that triggers delivery of an OTP code.
How to mitigate CVE-2026-31798
Install security update from vendor's website.