Vulnerability · Published Oct 12, 2026 · Assigned by OTRS
CVE-2026-78357Insufficient Session Revocation for JWT Authentication
Critical 9.1
In plain English
A critical-severity security flaw in OTRS from OTRS GmbH (former OTRS AG). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities).
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | otrs2 | no fix listed | UBUNTU-CVE-2026-78357 |
| Ubuntu:24.04:LTS | znuny | no fix listed | UBUNTU-CVE-2026-78357 |
| Ubuntu:26.04:LTS | znuny | no fix listed | UBUNTU-CVE-2026-78357 |
| Ubuntu:26.10 | znuny | no fix listed | UBUNTU-CVE-2026-78357 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| OTRS GmbH (former OTRS AG) | OTRS | 7.0.x8.0.x2023.x2024.x2025.x2026.x – through 2026.6.x |
Weakness: CWE-613 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N