GHSA-4mp9-239f-g9hg CVE-2026-59898
Netty: WebSockets V07/V08 handshaker missing Connection/Upgrade validation
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.44%
- Chance of exploitation in the next 30 days. Higher than 38.17% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
- Fix
4.2.16.Final- Upgrade io.netty:netty-codec-http to this version or later
Description
Summary
An 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.
Affected versions
Maven
| Package | Vulnerable | Fixed in |
|---|---|---|
| io.netty:netty-codec-http | >= 4.2.0.Final, < 4.2.16.Final |
4.2.16.Final |
| io.netty:netty-codec-http | < 4.1.136.Final |
4.1.136.Final |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
io.netty:netty-codec-http Maven → 4.2.16.Final
- maven
<dependency><groupId>io.netty</groupId><artifactId>netty-codec-http</artifactId><version>4.2.16.Final</version></dependency>- gradle
implementation("io.netty:netty-codec-http:4.2.16.Final")
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- Attack vector
- Network
- Attack complexity
- High
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- Low
- Integrity (subsequent systems)
- Low
- Availability (subsequent systems)
- None
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Weakness
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.
How to prevent it
- Implementation: Use a web server that employs a strict HTTP parsing procedure, such as Apache [REF-433].
- Implementation: Use only SSL communication.
- Implementation: Terminate the client session after each request.
- System Configuration: Turn all pages to non-cacheable.
References
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-8c42-7qj2-3j46 Netty Vulnerable to Cache Poisoning and Information Disclosure via CORS Vary Header Overwrite | High | Also affects io.netty:netty-codec-http |
| GHSA-gcjf-9mgh-3p7g Netty: CRLF Injection via Multipart Filename in Netty HttpPostRequestEncoder | Medium | Also affects io.netty:netty-codec-http |
| GHSA-q4f6-jm68-57ww Netty: [HttpContentEncoder] Unbounded Per-Connection Queue Growth via HTTP/1.1 Pipelining Leads to Denial of Service | High | Also affects io.netty:netty-codec-http |
| GHSA-6cqp-g7gg-8hr5 Netty: Security Control Bypass via CORS Short-Circuit Failure | Medium | Also affects io.netty:netty-codec-http |
| GHSA-jppx-w49h-x2qq Netty: [SpdyHttpDecoder] ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion | High | Also affects io.netty:netty-codec-http |
| GHSA-mvh2-crg5-v77c Netty SPDY zlib header block continues decoded expansion after maxHeaderSize truncation | High | Also affects io.netty:netty-codec-http |
| GHSA-6jqx-86gh-f27w Netty SPDY SETTINGS frame count materializes unbounded settings map | High | Also affects io.netty:netty-codec-http |
| GHSA-hvcg-qmg6-jm4c Netty: HttpObjectDecoder skips arbitrary initial control characters when only initial CRLF characters are permitted | Medium | Also affects io.netty:netty-codec-http |
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