Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-q4f6-jm68-57ww
Advisory ID github_osv/GHSA-q4f6-jm68-57ww
Aliases CVE-2026-59899
Summary Netty: [HttpContentEncoder] Unbounded Per-Connection Queue Growth via HTTP/1.1 Pipelining Leads to Denial of Service ### Impact `HttpContentEncoder` (the superclass of the production handler `HttpContentCompressor`) maintains a per-channel `ArrayDeque<CharSequence>` named `acceptEncodingQueue` that accumulates attacker-controlled data without any size limit. The queue is filled on the I/O thread for every inbound HTTP request and drained only when the application later writes a non-1xx response. This creates a resource exhaustion vulnerability when an attacker exploits HTTP/1.1 pipelining to flood the connection with requests faster than the application produces responses.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-770 Allocation of Resources Without Limits or Throttling
System Score Found at
cvssv4 6.9 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-q4f6-jm68-57ww/GHSA-q4f6-jm68-57ww.json
generic_textual MODERATE
Reference id Reference type URL
https://github.com/netty/netty
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-q4f6-jm68-57ww
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-q4f6-jm68-57ww/GHSA-q4f6-jm68-57ww.json
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.