CVE-2026-18661 In Eclipse Jetty, across various versions of `jetty-annotations`, and `jetty-eeN-annotations`, the Jakarta Spec authoritative url-pattern ru
Attackers can bypass security constraints in Eclipse Jetty when specific web.xml and annotation configurations are used, potentially accessing protected resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-18661?
CVE-2026-18661 is a high-severity missing authorization vulnerability, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In Eclipse Jetty, across various versions of `jetty-annotations`, and `jetty-eeN-annotations`, the Jakarta Spec authoritative url-pattern rules for mixed `@ServletSecurity` annotation, and `web.xml` defined `security-constraint` on the same `url-pattern` were not being applied if the `web.xml` had more than 1 `url-pattern` for a servlet, and had a `security-constraint` applying to only some of those `url-pattern` definitions.
Weakness: CWE-863
Which versions are affected by CVE-2026-18661?
How do I fix CVE-2026-18661?
Apply the vendor's patch.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-18661 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18661 exists.
Sources
Also known as DEBIAN-CVE-2026-18661, GHSA-gvw6-wq7h-rwp3, GHSA-v6xf-996f-c35f, UBUNTU-CVE-2026-18661.