CVE-2026-41715 Reactor Netty HTTP Client Leaks Credentials On Protocol Downgrade Redirect
Attackers can steal credentials when Reactor Netty follows redirects from HTTPS to HTTP, requiring explicit redirect configuration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-41715?
CVE-2026-41715 is a medium-severity vulnerability in Spring Reactor Netty, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
In specific scenarios involving HTTP redirects from a secure to an insecure endpoint, the Reactor Netty HTTP client may leak credentials. In order for this to happen, the HTTP client must have been explicitly configured to follow redirects.
Affected versions: Reactor Netty 1.0.0 through 1.0.51; 1.1.0 through 1.1.35; 1.2.0 through 1.2.17; 1.3.0 through 1.3.5.
Weakness: CWE-522
Which versions are affected by CVE-2026-41715?
8 open source packages ship an affected version, including io.projectreactor.netty:reactor-netty.
| Package | Affected | Fixed in |
|---|---|---|
io.projectreactor.netty:reactor-netty Maven | From 1.0.0 to 1.0.48 | None |
io.projectreactor.netty:reactor-netty Maven | From 1.0.0 to 1.0.48 | None |
io.projectreactor.netty:reactor-netty Maven | From 1.1.0 to 1.1.31 | None |
io.projectreactor.netty:reactor-netty Maven | From 1.1.0 to 1.1.31 | None |
io.projectreactor.netty:reactor-netty Maven | From 1.2.0 | 1.2.18 |
io.projectreactor.netty:reactor-netty Maven | From 1.2.0 | 1.2.18 |
2 more packages
io.projectreactor.netty:reactor-netty Maven | From 1.3.0 | 1.3.6 |
io.projectreactor.netty:reactor-netty Maven | From 1.3.0 | 1.3.6 |
How do I fix CVE-2026-41715?
Upgrade io.projectreactor.netty:reactor-netty to a fixed version for your release line: 1.2.18 or 1.3.6.
Is CVE-2026-41715 being exploited?
There is no known exploitation of CVE-2026-41715 in the wild and no public exploit code.
Sources
Also known as CLEANSTART-2026-RO34995, CLSA-2026-1783645392, CLSA-2026-1783645399, CLSA-2026-1784769563, CLSA-2026-1786940280, CLSA-2026-1788524080 and 3 more.