CVE-2026-59898

EUVD-2026-50444

29.07.2026, 19:16

Netty is an asynchronous, event-driven network application framework.  Prior to versions 4.1.136.Final and 4.2.16.Final, ab attacker can force WebSocket upgrade via the lax V07 (or V08) handshaker by sending `Sec-WebSocket-Version: 7` and omitting `Connection: Upgrade` / `Upgrade: websocket` headers, completing a protocol switch that a proxy would not recognize as an Upgrade request and enabling HTTP request smuggling / protocol-confusion attacks. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.

HTTP Request/Response Smuggling

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Base Score

CVSS 3.x

EPSS Score

Percentile: 16.26%

Affected Products (NVD)

Vendor	Product	Version
netty	netty	𝑥 < 4.1.136
netty	netty	4.2.0 ≤ 𝑥 < 4.2.16

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

netty

bookworm	vulnerable
bookworm (security)	vulnerable
forky	vulnerable
sid	vulnerable
trixie	vulnerable
trixie (security)	vulnerable

Ubuntu Releases

Ubuntu Product

Codename

netty

bionic	needs-triage
focal	needs-triage
jammy	needs-triage
noble	needs-triage
resolute	needs-triage
trusty	needs-triage
xenial	needs-triage

openSUSE / SLES Releases

openSUSE Product

Release

netty-tcnative

suse enterprise desktop 15 SP7	2.0.80-150200.3.48.1 fixed
suse enterprise sap 15 SP4	2.0.80-150200.3.48.1 fixed
suse enterprise sap 15 SP5	2.0.80-150200.3.48.1 fixed
suse enterprise sap 15 SP6	2.0.80-150200.3.48.1 fixed
suse enterprise sap 15 SP7	2.0.80-150200.3.48.1 fixed
suse enterprise server 15 SP4	2.0.80-150200.3.48.1 fixed
suse enterprise server 15 SP5	2.0.80-150200.3.48.1 fixed
suse enterprise server 15 SP6	2.0.80-150200.3.48.1 fixed
suse enterprise server 15 SP7	2.0.80-150200.3.48.1 fixed

Common Weakness Enumeration

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

Vulnerability Media Exposure

[GERMAN] Netty: Mehrere Schwachstellen
Ein Angreifer kann mehrere Schwachstellen in Netty ausnutzen, um Sicherheitsprüfungen zu umgehen, Anfragen oder Header zu manipulieren, Zertifikatsprüfungen zu unterlaufen sowie einen Denial of Service zu verursachen.
Published: 2026-07-14T22:00:00+00:00

References

https://github.com/netty/netty/releases/tag/netty-4.1.136.Final

https://github.com/netty/netty/releases/tag/netty-4.2.16.Final

https://github.com/netty/netty/security/advisories/GHSA-4mp9-239f-g9hg