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Critical · 9.1 CVE-2026-78357 EUVD-2026-97267GHSA-f6jh-p427-pjq6

Insufficient Session Revocation for JWT Authentication

Published Oct 12, 2026 · Updated Oct 15, 2026 · Assigned by OTRS

Description

Previously issued authentication tokens are not immediately invalidated when an OTRS agent or customer user account is deactivated or its password is changed. As a result, an existing JWT may remain valid until its regular expiration time, which can be approximately 16 hours.

An attacker who has previously obtained a valid authentication token can therefore continue to access OTRS with the privileges of the affected agent or customer user even after the corresponding account has been deactivated or the user's password has been changed.

The vulnerability does not allow an attacker to obtain authentication tokens by itself. Exploitation requires possession of a previously issued and still valid token. The actual impact depends on the privileges associated with the compromised token. Customer user tokens are limited to the permissions of the affected customer account, while agent tokens may provide access to broader ticket, customer, or administrative functionality depending on the assigned permissions.

This issue affects OTRS:

* 7.0.X
* 8.0.X
* 2023.X
* 2024.X
* 2025.X
* 2026.X before 2026.7.X

Affected products

VendorProductAffectedFixed
OTRS GmbH (former OTRS AG) OTRS 7.0.x, 8.0.x, 2023.x, 2024.x, 2025.x, 2026.x – ≤ 2026.6.x —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Ubuntu 26.10 znuny No fix yet —
Ubuntu 26.04 LTS znuny No fix yet —
Ubuntu 24.04 LTS znuny No fix yet —
Ubuntu 22.04 LTS otrs2 No fix yet —
Ubuntu 20.04 LTS otrs2 No fix yet —
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 18.04 LTS otrs2 No fix yet —
Ubuntu 16.04 LTS otrs2 No fix yet —

Advisories 1

References