SB2026042798 - Multiple vulnerabilities in JumpServer



SB2026042798 - Multiple vulnerabilities in JumpServer

Published: April 27, 2026

Security Bulletin ID SB2026042798
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Improper Certificate Validation (CVE-ID: CVE-2026-31798)

CWE-ID: CWE-295 - Improper Certificate Validation

CVSSv4: 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


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.


2) Improper Neutralization of Special Elements Used in a Template Engine (CVE-ID: CVE-2026-31864)

CWE-ID: CWE-1336 - Improper Neutralization of Special Elements Used in a Template Engine

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to execute arbitrary code.

The vulnerability exists due to server-side template injection in yaml_load_with_i18n() in apps/common/utils/yml.py when processing user-uploaded YAML configuration files from Applet or VirtualApp ZIP packages. A remote privileged user can upload a specially crafted ZIP package containing a malicious manifest.yml file to execute arbitrary code.

User interaction is required for the upload and processing of an Applet or VirtualApp package.


Remediation

Install update from vendor's website.