Incorrect authorization in Jetty - CVE-2026-18661
Published: October 15, 2026
Vulnerability identifier: #VU155896
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-18661
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 access restrictions and potentially disclose sensitive information or perform unauthorized state-changing operations.
The vulnerability exists due to incorrect authorization in Jetty's ServletSecurityAnnotationHandler when processing a multi-mapped servlet whose deployment descriptor constrains only some of its URL mappings. A remote attacker can send requests to an alternate mapping whose ServletSecurity annotation has been incorrectly suppressed to bypass servlet access restrictions and potentially disclose sensitive information or perform unauthorized state-changing operations.
Affected software
Jetty
How to mitigate CVE-2026-18661
Install security update from vendor's website.
Jetty - addressed in versions 9.4.65, 10.0.33, 12.0.39, 12.1.12