GHSA-8f3q-3jmv-7prw

Suggest an improvement
Source
https://github.com/advisories/GHSA-8f3q-3jmv-7prw
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-8f3q-3jmv-7prw/GHSA-8f3q-3jmv-7prw.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-8f3q-3jmv-7prw
Aliases
Published
2026-09-15T20:00:36Z
Modified
2026-09-15T20:15:05Z
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 has an unbounded outbound frame queue
Details

Ember's HTTP/2 connection serializes all outgoing frames through a single unbounded queue drained by one writer fiber (writeLoop). When the write side stalls, any frames the connection keeps producing accumulate in that queue without limit. The peer can drive this cheaply because the connection emits a control frame in response to inbound frames it does not flow-control: one PING ACK per PING, one SETTINGS ACK per SETTINGS, and a WINDOW_UPDATE per inbound DATA. A single unauthenticated connection can therefore exhaust heap and OOM the process.

This affects an ember server (malicious client) and an ember client (malicious/compromised server that floods the client and stops reading its ACKs).

Impact

Unauthenticated remote denial of service (OOM) against any ember server built .withHttp2, from a single connection, at negligible attacker cost (tiny control frames). Also affects an ember client talking to a hostile HTTP/2 server.

Preconditions

  • Ember server or client built .withHttp2, speaking to a hostile or compromised peer.

Workarounds

  • Disable HTTP/2 (do not call .withHttp2).
Database specific 
{
    "cwe_ids": [
        "CWE-400",
        "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-15T20:00:36Z",
    "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-8f3q-3jmv-7prw/GHSA-8f3q-3jmv-7prw.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-8f3q-3jmv-7prw/GHSA-8f3q-3jmv-7prw.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-8f3q-3jmv-7prw/GHSA-8f3q-3jmv-7prw.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-8f3q-3jmv-7prw/GHSA-8f3q-3jmv-7prw.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-8f3q-3jmv-7prw/GHSA-8f3q-3jmv-7prw.json"