Advisory details:
gitlab / maven/io.netty/netty-codec-http/CVE-2026-50020
| Advisory ID | gitlab/maven/io.netty/netty-codec-http/CVE-2026-50020 |
| Aliases |
CVE-2026-50020
GHSA-hvcg-qmg6-jm4c |
| Summary | Netty: HttpObjectDecoder skips arbitrary initial control characters when only initial CRLF characters are permitted Before reading the first request-line, `HttpObjectDecoder` skips every byte for which `Character.isISOControl(b)` is `true` (0x00–0x1F and 0x7F) as well as all whitespace. RFC 9112 §2.2 only asks servers to ignore **empty CRLF lines** preceding the request-line — a carefully scoped robustness allowance intended to handle HTTP/1.0 POST workarounds. Silently absorbing NUL bytes, SOH, STX, and other non-CRLF control characters goes significantly beyond this, and can be exploited for request-boundary confusion in pipelined or multiplexed transports where a front-end component treats those bytes differently. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 0.0 |
| Risk | |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| System | Score | Found at |
|---|---|---|
| cvssv3.1 | https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/io.netty/netty-codec-http/CVE-2026-50020.yml |
| Reference id | Reference type | URL |
|---|---|---|
| https://github.com/netty/netty/releases/tag/netty-4.1.135.Final | ||
| https://github.com/netty/netty/releases/tag/netty-4.2.15.Final | ||
| CVE-2026-50020 | https://nvd.nist.gov/vuln/detail/CVE-2026-50020 | |
| GHSA-hvcg-qmg6-jm4c | https://github.com/advisories/GHSA-hvcg-qmg6-jm4c | |
| GHSA-hvcg-qmg6-jm4c | Other | https://github.com/netty/netty/security/advisories/GHSA-hvcg-qmg6-jm4c |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2026-06-12T15:56:10Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/50xxx/CVE-2026-50020.json
Source Advisory: vulnrichment/CVE-2026-50020
[{'Exploitation': 'poc'},
{'Automatable': 'yes'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]