GHSA-jfg9-48mv-9qgx

Suggest an improvement
Source
https://github.com/advisories/GHSA-jfg9-48mv-9qgx
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-jfg9-48mv-9qgx/GHSA-jfg9-48mv-9qgx.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-jfg9-48mv-9qgx
Aliases
  • CVE-2026-44248
Downstream
Related
Published
2026-05-07T05:14:14Z
Modified
2026-05-14T20:51:55.305572Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
Netty MQTT: Resource exhaustion in MqttDecoder
Details

Impact

The MQTT 5 header Properties section is parsed and buffered before any message size limit is applied.

Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded.

Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion.

This can cause high resource usage in both CPU and memory.

Resources

ANT-2026-09608 https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901027

Database specific 
{
    "github_reviewed_at": "2026-05-07T05:14:14Z",
    "nvd_published_at": "2026-05-13T19:17:27Z",
    "cwe_ids": [
        "CWE-400"
    ],
    "severity": "MODERATE",
    "github_reviewed": true
}
References

Affected packages

Maven / io.netty:netty-codec-mqtt

Package

Name
io.netty:netty-codec-mqtt
View open source insights on deps.dev
Purl
pkg:maven/io.netty/netty-codec-mqtt

Affected ranges

Type
ECOSYSTEM
Events
Introduced
4.2.0.Alpha1
Fixed
4.2.13.Final

Affected versions

4.*
4.2.0.Alpha1
4.2.0.Alpha2
4.2.0.Alpha3
4.2.0.Alpha4
4.2.0.Alpha5
4.2.0.Beta1
4.2.0.RC1
4.2.0.RC2
4.2.0.RC3
4.2.0.RC4
4.2.0.Final
4.2.1.Final
4.2.2.Final
4.2.3.Final
4.2.4.Final
4.2.5.Final
4.2.6.Final
4.2.7.Final
4.2.8.Final
4.2.9.Final
4.2.10.Final
4.2.11.Final
4.2.12.Final

Database specific

last_known_affected_version_range 
"<= 4.2.12.Final"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-jfg9-48mv-9qgx/GHSA-jfg9-48mv-9qgx.json"

Maven / io.netty:netty-codec-mqtt

Package

Name
io.netty:netty-codec-mqtt
View open source insights on deps.dev
Purl
pkg:maven/io.netty/netty-codec-mqtt

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.1.133.Final

Affected versions

4.*
4.1.0.Beta1
4.1.0.Beta2
4.1.0.Beta3
4.1.0.Beta4
4.1.0.Beta5
4.1.0.Beta6
4.1.0.Beta7
4.1.0.Beta8
4.1.0.CR1
4.1.0.CR2
4.1.0.CR3
4.1.0.CR4
4.1.0.CR5
4.1.0.CR6
4.1.0.CR7
4.1.0.Final
4.1.1.Final
4.1.2.Final
4.1.3.Final
4.1.4.Final
4.1.5.Final
4.1.6.Final
4.1.7.Final
4.1.8.Final
4.1.9.Final
4.1.10.Final
4.1.11.Final
4.1.12.Final
4.1.13.Final
4.1.14.Final
4.1.15.Final
4.1.16.Final
4.1.17.Final
4.1.18.Final
4.1.19.Final
4.1.20.Final
4.1.21.Final
4.1.22.Final
4.1.23.Final
4.1.24.Final
4.1.25.Final
4.1.26.Final
4.1.27.Final
4.1.28.Final
4.1.29.Final
4.1.30.Final
4.1.31.Final
4.1.32.Final
4.1.33.Final
4.1.34.Final
4.1.35.Final
4.1.36.Final
4.1.37.Final
4.1.38.Final
4.1.39.Final
4.1.40.Final
4.1.41.Final
4.1.42.Final
4.1.43.Final
4.1.44.Final
4.1.45.Final
4.1.46.Final
4.1.47.Final
4.1.48.Final
4.1.49.Final
4.1.50.Final
4.1.51.Final
4.1.52.Final
4.1.53.Final
4.1.54.Final
4.1.55.Final
4.1.56.Final
4.1.57.Final
4.1.58.Final
4.1.59.Final
4.1.60.Final
4.1.61.Final
4.1.62.Final
4.1.63.Final
4.1.64.Final
4.1.65.Final
4.1.66.Final
4.1.67.Final
4.1.68.Final
4.1.69.Final
4.1.70.Final
4.1.71.Final
4.1.72.Final
4.1.73.Final
4.1.74.Final
4.1.75.Final
4.1.76.Final
4.1.77.Final
4.1.78.Final
4.1.79.Final
4.1.80.Final
4.1.81.Final
4.1.82.Final
4.1.83.Final
4.1.84.Final
4.1.85.Final
4.1.86.Final
4.1.87.Final
4.1.88.Final
4.1.89.Final
4.1.90.Final
4.1.91.Final
4.1.92.Final
4.1.93.Final
4.1.94.Final
4.1.95.Final
4.1.96.Final
4.1.97.Final
4.1.98.Final
4.1.99.Final
4.1.100.Final
4.1.101.Final
4.1.102.Final
4.1.103.Final
4.1.104.Final
4.1.105.Final
4.1.106.Final
4.1.107.Final
4.1.108.Final
4.1.109.Final
4.1.110.Final
4.1.111.Final
4.1.112.Final
4.1.113.Final
4.1.114.Final
4.1.115.Final
4.1.116.Final
4.1.117.Final
4.1.118.Final
4.1.119.Final
4.1.120.Final
4.1.121.Final
4.1.122.Final
4.1.123.Final
4.1.124.Final
4.1.125.Final
4.1.126.Final
4.1.127.Final
4.1.128.Final
4.1.129.Final
4.1.130.Final
4.1.131.Final
4.1.132.Final

Database specific

last_known_affected_version_range 
"<= 4.1.132.Final"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-jfg9-48mv-9qgx/GHSA-jfg9-48mv-9qgx.json"