GHSA-6983-jfq8-485w

Suggest an improvement
Source
https://github.com/advisories/GHSA-6983-jfq8-485w
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6983-jfq8-485w/GHSA-6983-jfq8-485w.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-6983-jfq8-485w
Aliases
Published
2026-09-03T20:33:03Z
Modified
2026-09-03T20:45:04Z
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
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Phoenix: Unbounded channel joins per transport enables DoS over few connections
Details

Summary

Phoenix transports do not limit the number of channels in a given connection, making it easy to spawn hundreds of thousands of processes over a single connection, and, eventually reaching the max processes VM limit. The solution is to limit the number of channels per transport, so an attacker needs to start new HTTP/WebSocket connections, allowing third-party services to apply rate limits and intervene more easily.

Impact

An unauthenticated remote attacker can cause a denial of service against any Phoenix app that exposes LongPoll/WebSocket transports.

Database specific 
{
    "cwe_ids": [
        "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-03T20:33:03Z",
    "nvd_published_at": "2026-07-07T16:16:40Z",
    "severity": "HIGH"
}
References

Affected packages

Hex / phoenix

Package

Name
phoenix
Purl
pkg:hex/phoenix

Affected ranges

Type
SEMVER
Events
Introduced
0.11.0
Fixed
1.5.15

Affected versions

0.*
0.11.0
0.12.0
0.13.0
0.13.1
0.14.0
0.15.0
0.16.0
0.16.1
0.17.0
0.17.1
1.*
1.0.0
1.0.1
1.0.2
1.0.3
1.0.4
1.0.5
1.0.6
1.1.0
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.1.6
1.1.7
1.1.8
1.1.9
1.2.0-rc.0
1.2.0-rc.1
1.2.0
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.3.0-rc.0
1.3.0-rc.1
1.3.0-rc.2
1.3.0-rc.3
1.3.0
1.3.1
1.3.2
1.3.3
1.3.4
1.3.5
1.4.0-rc.0
1.4.0-rc.1
1.4.0-rc.2
1.4.0-rc.3
1.4.0
1.4.1
1.4.2
1.4.3
1.4.4
1.4.5
1.4.6
1.4.7
1.4.8
1.4.9
1.4.10
1.4.11
1.4.12
1.4.13
1.4.14
1.4.15
1.4.16
1.4.17
1.4.18
1.5.0-rc.0
1.5.0
1.5.1
1.5.2
1.5.3
1.5.4
1.5.5
1.5.6
1.5.7
1.5.8
1.5.9
1.5.10
1.5.11
1.5.12
1.5.13
1.5.14

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6983-jfq8-485w/GHSA-6983-jfq8-485w.json"

Hex / phoenix

Package

Name
phoenix
Purl
pkg:hex/phoenix

Affected ranges

Type
SEMVER
Events
Introduced
1.6.0-rc.0
Fixed
1.6.17

Affected versions

1.*
1.6.0-rc.0
1.6.0-rc.1
1.6.0
1.6.1
1.6.2
1.6.3
1.6.4
1.6.5
1.6.6
1.6.7
1.6.8
1.6.9
1.6.10
1.6.11
1.6.12
1.6.13
1.6.14
1.6.15
1.6.16

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6983-jfq8-485w/GHSA-6983-jfq8-485w.json"

Hex / phoenix

Package

Name
phoenix
Purl
pkg:hex/phoenix

Affected ranges

Type
SEMVER
Events
Introduced
1.7.0-rc.0
Fixed
1.7.24

Affected versions

1.*
1.7.0-rc.0
1.7.0-rc.1
1.7.0-rc.2
1.7.0-rc.3
1.7.0
1.7.1
1.7.2
1.7.3
1.7.4
1.7.5
1.7.6
1.7.7
1.7.8
1.7.9
1.7.10
1.7.11
1.7.12
1.7.13
1.7.14
1.7.15
1.7.16
1.7.17
1.7.18
1.7.19
1.7.20
1.7.21
1.7.22
1.7.23

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6983-jfq8-485w/GHSA-6983-jfq8-485w.json"

Hex / phoenix

Package

Name
phoenix
Purl
pkg:hex/phoenix

Affected ranges

Type
SEMVER
Events
Introduced
1.8.0-rc.0
Fixed
1.8.9

Affected versions

1.*
1.8.0-rc.0
1.8.0-rc.1
1.8.0-rc.2
1.8.0-rc.3
1.8.0-rc.4
1.8.0
1.8.1
1.8.2
1.8.3
1.8.4
1.8.5
1.8.6
1.8.7
1.8.8

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-6983-jfq8-485w/GHSA-6983-jfq8-485w.json"