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Advisory details: gitlab / maven/io.netty/netty-codec-http2/CVE-2026-47244
Advisory ID gitlab/maven/io.netty/netty-codec-http2/CVE-2026-47244
Aliases CVE-2026-47244
GHSA-5x3r-wrvg-rp6q
Summary Netty HTTP/2: Advertised MAX_CONCURRENT_STREAMS are not enforced 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.
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
Weaknesses (3)
CWE-400 Uncontrolled Resource Consumption
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3.1 https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/io.netty/netty-codec-http2/CVE-2026-47244.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
https://github.com/netty/netty/security/advisories/GHSA-5x3r-wrvg-rp6q
CVE-2026-47244 https://nvd.nist.gov/vuln/detail/CVE-2026-47244
GHSA-5x3r-wrvg-rp6q https://github.com/advisories/GHSA-5x3r-wrvg-rp6q
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://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/io.netty/netty-codec-http2/CVE-2026-47244.yml
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:N/A:Y/T:P/P:M/B:A/M:M/D:T/2026-06-12T14:59:00Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/47xxx/CVE-2026-47244.json

Source Advisory: vulnrichment/CVE-2026-47244

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'yes'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]