CVE-2019-16869 HTTP Request Smuggling in Netty
Netty mishandles whitespace in HTTP headers, enabling request smuggling attacks that bypass security controls or expose data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2019-16869?
CVE-2019-16869 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 26 Sep 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Netty before 4.1.42.Final mishandles whitespace before the colon in HTTP headers (such as a "Transfer-Encoding : chunked" line), which leads to HTTP request smuggling.
Weakness: CWE-444
Which versions are affected by CVE-2019-16869?
6 open source packages ship an affected version, including io.netty:netty, io.netty:netty-all and org.jboss.netty:netty. It affects 4 products.
| Package | Affected | Fixed in |
|---|---|---|
io.netty:netty Maven | From 3.3.0.Final to 4.0.0.Alpha8 | None |
io.netty:netty Maven | From 3.3.0.Final to 4.0.0.Alpha8 | None |
io.netty:netty-all Maven | From 4.0.0.Beta1 | 4.1.42.Final |
io.netty:netty-all Maven | From 4.0.0.Beta1 | 4.1.42.Final |
org.jboss.netty:netty Maven | All versions to 3.2.9.Final | None |
org.jboss.netty:netty Maven | All versions to 3.2.9.Final | None |
Products include Canonical Ubuntu Linux, Debian Debian Linux, Netty Netty, Redhat Jboss Enterprise Application Platform.
How do I fix CVE-2019-16869?
Upgrade to a fixed version.
Is CVE-2019-16869 being exploited?
There is no known exploitation of CVE-2019-16869 in the wild and no public exploit code.
Other vulnerabilities in Canonical Ubuntu Linux
Sources
Also known as CLEANSTART-2025-OT57592, CLEANSTART-2026-BC52687, DEBIAN-CVE-2019-16869, DLA-1941-1, DSA-4597-1, GHSA-p979-4mfw-53vg and 3 more.