Description
When Jetty's `HttpClient` make a request to a server through a forward proxy, the server may reply with a 407 (Proxy Authentication Required).
The client mistakenly interprets the 407 as coming from the proxy, so it re-sends the request with the `Proxy-Authentication` header, which arrives to the server, that now has access to the proxy credentials.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Eclipse Foundation | Eclipse Jetty | 12.1.0 – ≤ 12.1.12, 12.0.0 – ≤ 12.0.38, 11.0.0 – ≤ 11.0.32, 10.0.0 – ≤ 10.0.32, 9.4.0 – ≤ 9.4.64 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | jetty12 | 12.0.39-1 | — |
| Debian 14 | jetty9 | No fix yet | — |
| Debian 13 | jetty9 +1 | No fix yet | — |
| Debian 12 | jetty9 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | jetty | No fix yet | — |
| Ubuntu 14.04 LTS | jetty | No fix yet | — |
Advisories 1
- WID-SEC-2026-3992 Eclipse Jetty: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 5, 2026