Authentication bypass using an alternate path or channel in Jetty - CVE-2026-19863
Published: October 15, 2026
Vulnerability identifier: #VU155901
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-19863
CWE-ID: CWE-288
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass authentication and role constraints to access protected data or perform unauthorized actions.
The vulnerability exists due to unanchored login-path substring matching in Jetty's EthereumAuthenticator when identifying the public login page from canonical context-relative request paths. A remote attacker can send a request to a protected route containing the configured login path at a later path segment to bypass authentication and role constraints to access protected data or perform unauthorized actions.
Routes explicitly marked FORBIDDEN remain blocked.
Affected software
Jetty
How to mitigate CVE-2026-19863
Install security update from vendor's website.
Jetty - update to 12.1.13