SB2026100227 - Multiple vulnerabilities in YouTrack

CSH
CYBERSECURITY HELP
Sign In REGISTER

Main Vulnerability Database SB2026100227

SB2026100227 - Multiple vulnerabilities in YouTrack

Published: October 2, 2026

Security Bulletin ID SB2026100227
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 8
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 25% Low 75%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 8 vulnerabilities.


1) Incorrect authorization (CVE-ID: CVE-2026-100259)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to modify Gantt chart data.

The vulnerability exists due to improper access control in the Gantt chart feature when handling Gantt chart edit requests. A remote user can submit an edit request despite having view-only access to modify Gantt chart data.

Exploitation requires view-only access.


2) Missing Authorization (CVE-ID: CVE-2026-100258)

CWE-ID: CWE-862 - Missing Authorization

CVSSv4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to read project settings.

The vulnerability exists due to missing authorization in project settings access control when handling requests from read-only users. A remote user can request project settings to read project settings.


3) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2026-100257)

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

CVSSv4: 0 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to perform server-side request forgery.

The vulnerability exists due to stored XHTML injection in PDF export when exporting stored XHTML content. A remote attacker can inject crafted XHTML content and export it as a PDF to perform server-side request forgery.


4) Insecure Default Initialization of Resource (CVE-ID: CVE-2026-100260)

CWE-ID: CWE-1188 - Insecure Default Initialization of Resource

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to authenticate after a password reset.

The vulnerability exists due to insecure default initialization of a resource in the mailbox integration when processing authentication requests after a password reset. A remote attacker can use the mailbox integration to authenticate after a password reset.


5) Authentication bypass using an alternate path or channel (CVE-ID: CVE-2026-100261)

CWE-ID: CWE-288 - Authentication Bypass Using an Alternate Path or Channel

CVSSv4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to change article visibility settings.

The vulnerability exists due to improper authorization in article visibility settings when processing article visibility setting changes. A remote user can submit a visibility-setting change without update permission to change article visibility settings.


6) Incorrect authorization (CVE-ID: CVE-2026-100262)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to modify project notification templates.

The vulnerability exists due to improper authorization in project notification templates when handling template modification requests. A remote user can overwrite project notification templates to modify project notification templates.


7) Cross-site scripting (CVE-ID: CVE-2026-100263)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]


The vulnerability allows a remote attacker to inject arbitrary HTML content.

The vulnerability exists due to improper neutralization of user-controlled HTML in YouTrack when processing User-Agent headers. A remote attacker can send a request with a crafted User-Agent header to inject arbitrary HTML content.


8) Insufficiently protected credentials (CVE-ID: CVE-2026-100264)

CWE-ID: CWE-522 - Insufficiently Protected Credentials

CVSSv4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to disclose stored SMTP server credentials.

The vulnerability exists due to insufficiently protected credentials in the SMTP server configuration when changing the SMTP server host. A remote user can change the SMTP server host to disclose stored SMTP server credentials.


Remediation

Install update from vendor's website.

References