GHSA-6m4x-pp6q-5jmm

Suggest an improvement
Source
https://github.com/advisories/GHSA-6m4x-pp6q-5jmm
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6m4x-pp6q-5jmm/GHSA-6m4x-pp6q-5jmm.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-6m4x-pp6q-5jmm
Aliases
Published
2026-09-15T19:52:58Z
Modified
2026-09-15T20:00:39Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
Http4s Ember HTTP/2: unbounded inbound body buffering
Details

Ember's HTTP/2 stack replenishes the inbound flow-control window based on bytes received off the wire, not bytes consumed by the application. Received DATA is buffered in an unbounded per-stream channel. Flow control therefore provides no backpressure: a peer can stream a large or unbounded body faster than the application drains it and the connection retains every payload in heap.

This is the read-path mirror of the outbound queue issue.

This affects an Ember receiving a request body and an Ember client receiving a response body from a hostile server.

Impact

Unauthenticated remote denial of service (OOM) against any Ember server built .withHttp2 for a non-draining or slow-draining route, and against an Ember client consuming from a hostile or compromised server.

Workarounds

  • Disable HTTP/2 to remove the vector entirely.
  • Apply an aggregate request-entity size limit (e.g. EntityLimiter middleware) on routes that consume the body.
  • Ensure handlers fully drain request bodies with aggressive idle timeouts.
Database specific 
{
    "cwe_ids": [
        "CWE-400",
        "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-15T19:52:58Z",
    "nvd_published_at": null,
    "severity": "HIGH"
}
References

Affected packages

Maven
org.http4s:http4s-ember-core_2.12

Package

Name
org.http4s:http4s-ember-core_2.12
View open source insights on deps.dev
Purl
pkg:maven/org.http4s/http4s-ember-core_2.12

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.23.35

Affected versions

0.*
0.10.0-M10
0.21.0-M2
0.21.0-M3
0.21.0-M4
0.21.0-M5
0.21.0-M6
0.21.0-RC1
0.21.0-RC2
0.21.0-RC3
0.21.0-RC4
0.21.0-RC5
0.21.0
0.21.1
0.21.2
0.21.3
0.21.4
0.21.5
0.21.6
0.21.7
0.21.8
0.21.9
0.21.11
0.21.12
0.21.13
0.21.14
0.21.15
0.21.16
0.21.17
0.21.18
0.21.19
0.21.20
0.21.21
0.21.22
0.21.23
0.21.24
0.21.25
0.21.26
0.21.27
0.21.28
0.21.29
0.21.30
0.21.31
0.21.32
0.21.33
0.21.34
0.22.0-M1
0.22.0-M2
0.22.0-M3
0.22.0-M4
0.22.0-M5
0.22.0-M6
0.22.0-M7
0.22.0-M8
0.22.0-RC1
0.22.0
0.22-53-01128f5
0.22-96-55d3184
0.22-129-24d065b
0.22-143-49b5a8d
0.22.1
0.22.2
0.22.3
0.22.4
0.22.5
0.22.6
0.22.7
0.22.8
0.22.9
0.22.10
0.22.11
0.22.12
0.22.13
0.22.14
0.22.15
0.23.0-M1
0.23.0-RC1
0.23.0
0.23.1
0.23.2
0.23.3
0.23.4
0.23.5
0.23.6
0.23.7
0.23.8
0.23.9
0.23.10
0.23.11
0.23.12
0.23.13
0.23.14
0.23.15
0.23.16
0.23.17
0.23.18
0.23.19-RC1
0.23.19-RC2
0.23.19-RC3
0.23.19
0.23.20
0.23.21
0.23.22
0.23.23
0.23.24
0.23.25
0.23.26
0.23.27
0.23.28
0.23.29
0.23.30
0.23.31
0.23.32
0.23.33
0.23.34

Database specific

last_known_affected_version_range 
"<= 0.23.34"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6m4x-pp6q-5jmm/GHSA-6m4x-pp6q-5jmm.json"
org.http4s:http4s-ember-core_2.13

Package

Name
org.http4s:http4s-ember-core_2.13
View open source insights on deps.dev
Purl
pkg:maven/org.http4s/http4s-ember-core_2.13

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.23.35

Affected versions

0.*
0.10.0-M10
0.21.0-M2
0.21.0-M3
0.21.0-M4
0.21.0-M5
0.21.0-M6
0.21.0-RC1
0.21.0-RC2
0.21.0-RC3
0.21.0-RC4
0.21.0-RC5
0.21.0
0.21.1
0.21.2
0.21.3
0.21.4
0.21.5
0.21.6
0.21.7
0.21.8
0.21.9
0.21.11
0.21.12
0.21.13
0.21.14
0.21.15
0.21.16
0.21.17
0.21.18
0.21.19
0.21.20
0.21.21
0.21.22
0.21.23
0.21.24
0.21.25
0.21.26
0.21.27
0.21.28
0.21.29
0.21.30
0.21.31
0.21.32
0.21.33
0.21.34
0.22.0-M1
0.22.0-M2
0.22.0-M3
0.22.0-M4
0.22.0-M5
0.22.0-M6
0.22.0-M7
0.22.0-M8
0.22.0-RC1
0.22.0
0.22-53-01128f5
0.22-96-55d3184
0.22-129-24d065b
0.22-143-49b5a8d
0.22.1
0.22.2
0.22.3
0.22.4
0.22.5
0.22.6
0.22.7
0.22.8
0.22.9
0.22.10
0.22.11
0.22.12
0.22.13
0.22.14
0.22.15
0.23.0-M1
0.23.0-RC1
0.23.0
0.23.1
0.23.2
0.23.3
0.23.4
0.23.5
0.23.6
0.23.7
0.23.8
0.23.9
0.23.10
0.23.11
0.23.12
0.23.13
0.23.14
0.23.15
0.23.16
0.23.17
0.23.18
0.23.19-RC1
0.23.19-RC2
0.23.19-RC3
0.23.19
0.23.20
0.23.21
0.23.22
0.23.23
0.23.24
0.23.25
0.23.26
0.23.27
0.23.28
0.23.29
0.23.30
0.23.31
0.23.32
0.23.33
0.23.34

Database specific

last_known_affected_version_range 
"<= 0.23.34"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6m4x-pp6q-5jmm/GHSA-6m4x-pp6q-5jmm.json"
org.http4s:http4s-ember-core_3

Package

Name
org.http4s:http4s-ember-core_3
View open source insights on deps.dev
Purl
pkg:maven/org.http4s/http4s-ember-core_3

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.23.35

Affected versions

0.*
0.22.0-M8
0.22.0-RC1
0.22.0
0.22.1
0.22.2
0.22.3
0.22.4
0.22.5
0.22.6
0.22.7
0.22.8
0.22.9
0.22.10
0.22.11
0.22.12
0.22.13
0.22.14
0.22.15
0.23.0-M1
0.23.0-RC1
0.23.0
0.23.1
0.23.2
0.23.3
0.23.4
0.23.5
0.23.6
0.23.7
0.23.8
0.23.9
0.23.10
0.23.11
0.23.12
0.23.13
0.23.14
0.23.15
0.23.16
0.23.17
0.23.18
0.23.19-RC1
0.23.19-RC2
0.23.19-RC3
0.23.19
0.23.20
0.23.21
0.23.22
0.23.23
0.23.24
0.23.25
0.23.26
0.23.27
0.23.28
0.23.29
0.23.30
0.23.31
0.23.32
0.23.33
0.23.34

Database specific

last_known_affected_version_range 
"<= 0.23.34"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6m4x-pp6q-5jmm/GHSA-6m4x-pp6q-5jmm.json"
org.http4s:http4s-ember-core_2.13

Package

Name
org.http4s:http4s-ember-core_2.13
View open source insights on deps.dev
Purl
pkg:maven/org.http4s/http4s-ember-core_2.13

Affected ranges

Type
ECOSYSTEM
Events
Introduced
1.0.0-M1
Fixed
1.0.0-M47

Affected versions

1.*
1.0.0-M2
1.0.0-M3
1.0.0-M4
1.0.0-M5
1.0.0-M6
1.0.0-M7
1.0.0-M8
1.0.0-M9
1.0.0-M10
1.0.0-M11
1.0.0-M13
1.0.0-M14
1.0.0-M15
1.0.0-M16
1.0.0-M17
1.0.0-M18
1.0.0-M19
1.0.0-M20
1.0.0-M21
1.0.0-M22
1.0.0-M23
1.0.0-M24
1.0.0-M25
1.0.0-M27
1.0.0-M28
1.0.0-M29
1.0.0-M30
1.0.0-M31
1.0.0-M32
1.0.0-M33
1.0.0-M34
1.0.0-M35
1.0.0-M36
1.0.0-M37
1.0.0-M38
1.0.0-M39
1.0.0-M40
1.0.0-M41
1.0.0-M42
1.0.0-M43
1.0.0-M44
1.0.0-M45
1.0.0-M46

Database specific

last_known_affected_version_range 
"<= 1.0.0-M46"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6m4x-pp6q-5jmm/GHSA-6m4x-pp6q-5jmm.json"
org.http4s:http4s-ember-core_3

Package

Name
org.http4s:http4s-ember-core_3
View open source insights on deps.dev
Purl
pkg:maven/org.http4s/http4s-ember-core_3

Affected ranges

Type
ECOSYSTEM
Events
Introduced
1.0.0-M1
Fixed
1.0.0-M47

Affected versions

1.*
1.0.0-M22
1.0.0-M23
1.0.0-M24
1.0.0-M25
1.0.0-M27
1.0.0-M28
1.0.0-M29
1.0.0-M30
1.0.0-M31
1.0.0-M32
1.0.0-M33
1.0.0-M34
1.0.0-M35
1.0.0-M36
1.0.0-M37
1.0.0-M38
1.0.0-M39
1.0.0-M40
1.0.0-M41
1.0.0-M42
1.0.0-M43
1.0.0-M44
1.0.0-M45
1.0.0-M46

Database specific

last_known_affected_version_range 
"<= 1.0.0-M46"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6m4x-pp6q-5jmm/GHSA-6m4x-pp6q-5jmm.json"