# Reactor Netty HTTP Client Leaks Credentials On Protocol Downgrade Redirect

Advisory record · `GHSA-pfc9-2cqg-9wq6`

- **Identifiers:** `GHSA-pfc9-2cqg-9wq6` · `CVE-2026-41715`
- **State:** Confirmed
- **Severity:** CVSS 6.1 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-522](https://cwe.mitre.org/data/definitions/522.html)
- **Tags:** [Hard-coded credentials](https://agentprime.io/advisories/tag/hard-coded-credentials.md)
- **Published:** 9 Jun 2026
- **Updated:** 29 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 9 Jun 2026, 06:31 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `io.projectreactor.netty:reactor-netty` (Maven): affected `>=1.3.0, <1.3.6 || >=1.2.0, <1.2.18 || >=1.1.0, <=1.1.31 || >=1.0.0, <=1.0.48`; fixed in `1.3.6`, `1.2.18`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Reactor Netty (io.projectreactor.netty:reactor-netty) versions 1.0.0 through 1.0.51, 1.1.0 through 1.1.35, 1.2.0 through 1.2.17, and 1.3.0 through 1.3.5 are affected. When the HTTP client is explicitly configured to follow redirects, a redirect from a secure endpoint to an insecure one can cause credentials to be leaked. Upgrade to version 1.3.6 or 1.2.18, or to a later release in your line.

Written 2 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 6.1 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`, from CNA (vmware)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0018, the 7th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:19 UTC: First seen by agentprime
- 31 Oct 2026, 14:19 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-pfc9-2cqg-9wq6)

## Sources

- [GitHub Advisory Database: GHSA-pfc9-2cqg-9wq6](https://github.com/advisories/GHSA-pfc9-2cqg-9wq6)
- [OSV: GHSA-pfc9-2cqg-9wq6](https://osv.dev/vulnerability/GHSA-pfc9-2cqg-9wq6)
- <https://nvd.nist.gov/vuln/detail/CVE-2026-41715>
- <https://github.com/reactor/reactor-netty/commit/e7ef551eead84ba465324531683fafa03ab96ee9>
- <https://github.com/reactor/reactor-netty>
- <https://github.com/reactor/reactor-netty/releases/tag/v1.2.18>
- <https://github.com/reactor/reactor-netty/releases/tag/v1.3.6>
- <https://spring.io/security/cve-2026-41715>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-pfc9-2cqg-9wq6>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-pfc9-2cqg-9wq6/>. Everything for agents: <https://agentprime.io/llms.txt>.