EUVD-2026-37079
GHSA-6cj6-2fg2-2r4g
Severity by source
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
AC:H reflects the required auxiliary step of injecting a known session token into the victim's browser; UI:R for victim login; C/I:L scoped to single account; no availability impact.
Primary rating from Vendor (INCIBE).
CVSS VectorVendor: INCIBE
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
1DescriptionCVE.org
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.
AnalysisAI
Session fixation in osTicket v1.18.2 enables remote attackers to hijack authenticated user accounts by pre-seeding a known OSTSESSID cookie before the victim logs in. The application fails to invalidate or regenerate the session identifier upon successful authentication, so an attacker who plants a known token in the victim's browser retains access to that session once the victim authenticates. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires two sequential preconditions. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 base score of 5.1 (Medium) with vector AV:N/AC:L/AT:N/PR:N/UI:A accurately captures network reachability and no attacker privileges, but the AC:L designation understates the practical difficulty: the attacker must successfully deliver a pre-known session identifier into the victim's browser before login, which requires an auxiliary vector such as URL session injection, subdomain cookie injection, or a separate XSS flaw. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker anonymously visits the osTicket portal to obtain a valid pre-authentication OSTSESSID, then delivers this token to the victim's browser via a crafted phishing URL or a cookie-injection technique targeting the application's domain. The victim follows the link and logs in normally; because osTicket does not rotate the session ID at login, the attacker's pre-seeded OSTSESSID now maps to a fully authenticated session. … |
| Remediation | A vendor-released patch is confirmed as available per the INCIBE advisory; administrators should upgrade to the fixed osTicket release described at https://www.incibe.es/en/incibe-cert/notices/aviso/session-fixation-vulnerability-enhancesofts-osticket. … Detailed patch versions, workarounds, and compensating controls in full report. |
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