CVE-2023-41900: Jetty is a Java based web server and servlet engine.

Jetty is a Java based web server and servlet engine.

Jetty is a Java based web server and servlet engine. Versions 9.4.21 through 9.4.51, 10.0.15, and 11.0.15 are vulnerable to weak authentication. If a Jetty `OpenIdAuthenticator` uses the optional nested `LoginService`, and that `LoginService` decides to revoke an already authenticated user, then the current request will still treat the user as authenticated. The authentication is then cleared from the session and subsequent requests will not be treated as authenticated. So a request on a previously authenticated session could be allowed to bypass authentication after it had been rejected by the `LoginService`. This impacts usages of the jetty-openid which have configured a nested `LoginService` and where that `LoginService` will is capable of rejecting previously authenticated users. Versions 9.4.52, 10.0.16, and 11.0.16 have a patch for this issue.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses jetty.project, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.92%, higher than 60% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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