CVE-2026-93575: Netty's MqttDecoder
Affects nettySource GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 8 Nov 2026, 23:24 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10nettypkg:deb/ubuntu/netty?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu Pro 26.04 LTSnettypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/resoluteOther threats | Affected
| Fixed in– |
Ubuntu Pro 24.04 LTSnettypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSnettypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSnettypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSnettypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a patch is available, consider restricting access to MQTT services or applying network-level controls to mitigate potential exploitation.
Description
A vulnerability in Netty's MqttDecoder allows an unauthenticated remote attacker to send a specially crafted MQTT CONNECT packet that bypasses size validation checks. This leads to excessive memory and CPU consumption, causing a denial of service (DoS) via an OutOfMemoryError. The issue affects multiple specific versions of Netty. The CVSS score is 7.5, indicating medium severity.
References
- ubuntu.com/security/CVE-2026-93575 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-93575 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2536967 (opens in a new tab)
- github.com/netty/netty/security/advisories/GHSA-jqf3-r9ww-c5x8 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-93575 (opens in a new tab)