CVE-2026-9507 PUBLISHED

Session fixation vulnerability in Enhancesoft's osTicket

Assigner: INCIBE
Reserved: 25.05.2026 Published: 16.06.2026 Updated: 16.06.2026

A session fixation vulnerability has been identified in osTicket v1.18.2. This security flaw allows an attacker to hijack a victim’s account by keeping the initial session identifier (OSTSESSID) active after a successful login.

The issue lies in the fact that the application does not invalidate the pre-authentication cookie or generate a new identifier for the authenticated context. As a result, if an attacker manages to set a known session identifier in the victim’s browser, they will be able to maintain unauthorised access to the account once the victim has authenticated.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS Score: 5.1

Product Status

Vendor Enhancesoft
Product osTicket
Versions Default: unaffected
  • Version 1.18.2 is affected

Solutions

The current (legacy) source code is in maintenance mode, whilst Enhancesoft is focusing on a complete rewrite of the code (v2.0). This means that release cycles and security updates for the legacy code have been significantly delayed.

Credits

  • Mario Valiente finder

References

Problem Types

  • CWE-38 Path traversal: '\absolute\pathname\here' CWE