CVE-2026-44248
📛 CVE Title
Netty: Resource exhaustion in MqttDecoder
Description
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, 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. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- MEDIUM
- CVSS score
- 5.3 / 10
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L- Effective score
- 5.3 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-400 - Reserved
- 2026-05-05
- Published
- 2026-05-13 20:23 UTC
- Last updated
- 2026-05-13 21:16 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/44xxx/CVE-2026-44248.json
- Linked Threat
- CVE-2026-44248 — CVE-2026-44248
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-13 19:17:27 UTC
- NVD last modified
- 2026-05-18 12:15:48 UTC
- NVD CVSS v3.1
- 5.3 / 10 MEDIUM source: security-advisories@github.com
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 1.4 / 10
- EPSS score
- 0.0002 (probability of exploitation in next 30 days)
- EPSS percentile
- 4.93% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 08:42 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-30132 - Assigner
- GitHub_M
- Published
- May 13, 2026, 6:23:37 PM
- Updated
- May 13, 2026, 7:16:58 PM
- EUVD base score (CVSS 3.1)
-
5.3 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - EUVD-reported EPSS
- 0.0200
- Vendors
- io.netty, netty
- Products
-
netty-codec-mqtt (< 4.1.133.Final)netty-codec-mqtt (4.2.0.Alpha1, < 4.2.13.Final)netty (4.2.0.Alpha1, < 4.2.13.Final)netty (< 4.1.133.Final)
- Aliases
-
GHSA-jfg9-48mv-9qgx
ENISA description: Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, 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. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
EUVD references (1)
Affected products (2)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| netty | netty |
>= 4.2.0.Alpha1, < 4.2.13.Final (affected),
< 4.1.133.Final (affected)
|
— |
| io.netty | netty-codec-mqtt |
>= 4.2.0.Alpha1, < 4.2.13.Final (affected),
< 4.1.133.Final (affected)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/netty/netty/security/advisories/GHSA-jfg9-48mv-9qgx x_refsource_CONFIRM
MITRE references (1) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
- https://github.com/netty/netty/security/advisories/GHSA-jfg9-48mv-9qgx x_refsource_CONFIRM
Web references (3)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://nvd.nist.gov/vuln/detail/CVE-2026-44248 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-44248 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (1)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/netty/netty/security/advisories/GHSA-jfg9-48mv-9qgx security-advisories@github.com Vendor Advisory
Remediations (18)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:access.redhat.com
Learn about our open source products, services, and company. You are here
2026-05-23 20:54 UTC -
web:blog.qualys.com
With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.
2026-05-23 20:54 UTC -
web:en-forum.guildwars2.com
04/14/2026—April 14 Release Notes Note to users of third-party programs: The game may not launch or work properly after we release a new build if you use a third-party program, due to possible incompatibilities. ArenaNet cannot offer support if a third-party modification breaks, interferes with, ...
2026-05-23 20:54 UTC -
web:oradba.ch
19c 26ai cve oracle-cpu patch -management release-update security Oracle CPU April 2026 : Delayed RUs & First Analysis On April 21, 2026 , Oracle released the Critical Patch Update (CPU) for April 2026 — 481 new security fixes across the entire Oracle product stack. For Oracle Database, this means another round of mandatory patching.
2026-05-23 20:54 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 20:54 UTC -
web:support.servicenow.com
Overview The advisories below document publicly disclosed Common Vulnerabilities and Exposures ( CVEs ) in the Now Platform by ServiceNow. Because ServiceNow uses various methods to communicate vulnerability information, patches, and other fixes, customers should review family, security patch , and hotfix release notes, which are available at https://docs.servicenow.com, for a complete list of ...
2026-05-23 20:54 UTC -
web:www.crowdstrike.com
Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.
2026-05-23 20:54 UTC -
web:www.nickiswift.com
Carrie Underwood's carefully crafted image has hit a rough patch . Political controversy, fan backlash, and TV drama reshaped how the country star is viewed.
2026-05-23 20:54 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-23 20:54 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-23 20:54 UTC -
web:feedly.com
Welcome to Feedly CVEs — Research critical vulnerabilities ( CVEs ) with all the real-time and historical information you need to assess the risk to your organization. This free resource uses Feedly's AI to synthesize and analyze vulnerability information from across the web, including estimating CVSS scores up to 3 days before it's reported to the NVD.
2026-05-26 02:52 UTC -
web:integsec.com
A technical appendix below provides detection, remediation , and best‑practice guidance for your security and IT teams. S1 — Background & History CVE‑2026‑42898 was publicly disclosed on May 12, 2026 , and is assigned to an improper control of code generation in Microsoft Dynamics 365 on‑premises.
2026-05-26 02:52 UTC -
web:techcommunity.microsoft.com
We wanted to tell you how to address the Exchange Server May 2026 vulnerability CVE - 2026 -42897.
2026-05-26 02:52 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-05-26 02:52 UTC -
web:www.crowdstrike.com
Microsoft has released security updates for 130 vulnerabilities, including 30 critical, in its May 2026 Patch Tuesday rollout.
2026-05-26 02:52 UTC -
web:www.forbes.com
Updated May 17: This article, originally published May 16, has been updated to include further details on the emergency mitigation process recommended after the CVE - 2026 -42897 Microsoft Exchange ...
2026-05-26 02:52 UTC -
web:www.helpnetsecurity.com
Two flaws ( CVE - 2026 -42248, CVE - 2026 -42249) in Ollama's Windows auto-updater may allow an attacker to covertly plant a persistent executable.
2026-05-26 02:52 UTC -
web:www.secure.com
Learn the difference between vulnerability remediation and mitigation , and how a risk-based strategy can strengthen your security posture.
2026-05-26 02:52 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-44248.json.
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