Incorrect authorization in Jetty - CVE-2026-18662
Published: October 15, 2026
Vulnerability identifier: #VU155895
CSH Severity: Medium
CVSS v4: 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]
CVE-ID: CVE-2026-18662
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass servlet authorization constraints.
The vulnerability exists due to overwriting rather than combining applicable security constraints in Jetty's ConstraintSecurityHandler.processConstraintMappingWithMethodOmissions() when processing mappings with identical method-omission keys. A remote attacker can send a request using a non-omitted HTTP method to bypass servlet authorization constraints.
Exploitation requires a static application configuration in which a permissive mapping is processed after a deny or role-restricted mapping with the same omission key. The attacker does not control descriptor processing order.
Affected software
Jetty
How to mitigate CVE-2026-18662
Install security update from vendor's website.
Jetty - addressed in versions 9.4.65, 10.0.33, 12.0.39, 12.1.12