Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-5x3r-wrvg-rp6q
Advisory ID github_osv/GHSA-5x3r-wrvg-rp6q
Aliases CVE-2026-47244
Summary Netty HTTP/2: Advertised MAX_CONCURRENT_STREAMS are not enforced ### Impact DefaultHttp2Connection.DefaultEndpoint initialises maxActiveStreams/maxStreams to Integer.MAX_VALUE, and Http2Settings never inserts SETTINGS_MAX_CONCURRENT_STREAMS by default (Http2Settings.java:305-307 only clamps a user-supplied value). Unless the application explicitly calls initialSettings().maxConcurrentStreams(n), a Netty HTTP/2 server advertises no limit and enforces none locally. Each open stream allocates a DefaultStream object, PropertyMap slots, flow-controller state and IntObjectHashMap entry; with ~2^30 permissible odd stream IDs a single TCP connection can create hundreds of thousands of long-lived stream objects. This is also the precondition for CVE-2023-44487-style Rapid-Reset amplification, where the absence of a low concurrent cap multiplies backend work. ### Resources https://www.rfc-editor.org/rfc/rfc7540.html#section-6.5.2
Status Published
Exploitability 0.5
Weighted Severity 4.8
Risk 2.4
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-5x3r-wrvg-rp6q/GHSA-5x3r-wrvg-rp6q.json
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

There are no SSVC decisions available.