# CVE-2026-77711: Information disclosure in Eclipse Jetty

> Jetty HttpClient leaks proxy credentials to the target server when a 407 response is received, exposing sensitive authentication data.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-77711, GHSA-r2c5-3p8g-wpvw, GHSA-vv2w-r86m-5w27, UBUNTU-CVE-2026-77711

## What is CVE-2026-77711?

CVE-2026-77711 is a high-severity vulnerability in Eclipse Jetty, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-77711?


## How do I fix CVE-2026-77711?

Apply the vendor's patch.

## Is CVE-2026-77711 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77711 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77711 and fix it if it is affected.

What it is: CVE-2026-77711 is a high-severity vulnerability in Eclipse Jetty, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77711 exists.

Affected product: Eclipse Jetty. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-77711/ (Markdown: https://insights.sbomify.com/CVE-2026-77711/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77711
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77711
- OSV: https://osv.dev/vulnerability/CVE-2026-77711

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77711/
Summaries are generated and may contain mistakes; the official description above is the record.