Public vulnerability disclosure
CVE-2026-93491
Io.netty/netty-codec-http: netty: denial of service via unbounded httpservercodec http/1.1 pipeline queue
publishedCWE-770
A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption and a denial of service due to memory exhaustion.
Technical severity7.5 highCVSS 3.1 · CNA: redhat
Published2026-09-18Source updated 2026-11-06
Collected2026-11-063 attributed sources
Fixes and workarounds
Workaround
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Build of Apache Camel 3.33.3.SP2 Red Hat io.netty/netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
≥ 4.1.138.Final-redhat-00001; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Build of Debezium 3.6 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat build of Keycloak 26.4 Red Hat rhbk/keycloak-operator-bundle
https://catalog.redhat.com/software/containers/ |
≥ 26.4.17-2; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat build of Keycloak 26.4 Red Hat rhbk/keycloak-rhel9
https://catalog.redhat.com/software/containers/ |
≥ 26.4-29; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat build of Keycloak 26.4 Red Hat rhbk/keycloak-rhel9-operator
https://catalog.redhat.com/software/containers/ |
≥ 26.4-30; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat build of Keycloak 26.4.17 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat build of Keycloak 26.6 Red Hat rhbk/keycloak-operator-bundle
https://catalog.redhat.com/software/containers/ |
≥ 26.6.8-2; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat build of Keycloak 26.6 Red Hat rhbk/keycloak-rhel9
https://catalog.redhat.com/software/containers/ |
≥ 26.6-24; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat build of Keycloak 26.6 Red Hat rhbk/keycloak-rhel9-operator
https://catalog.redhat.com/software/containers/ |
≥ 26.6-24; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat build of Keycloak 26.6.8 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat build of Quarkus 3.27.5.SP2 Red Hat netty-codec-http
https://access.redhat.com/jbossnetwork/restricted/listSoftware.html |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat build of Quarkus 3.33.3.SP2 Red Hat netty-codec-http
https://access.redhat.com/jbossnetwork/restricted/listSoftware.html |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat JBoss Enterprise Application Platform 8.1 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unaffected |
CNA: redhat |
| Red Hat AMQ Broker 7 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat AMQ Clients Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat build of Apache Camel 4 for Quarkus 3 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat build of Apache Camel for Spring Boot 4 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat build of Apicurio Registry 3 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Data Grid 8 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Fuse 7 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unknown |
CNA: redhat |
| Red Hat JBoss Enterprise Application Platform 7 Red Hat netty-codec-http
https://access.redhat.com/jbossnetwork/restricted/listSoftware.html |
Range not reported
Other versions: unknown |
CNA: redhat |
| Red Hat Single Sign-On 7 Red Hat netty-codec-http
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 7.5 high |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA: redhat |
| 3.1 / 7.5 high |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://access.redhat.com/errata/RHSA-2026:69440CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:69470CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:70257CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:83612CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:95759CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:95760CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:95761CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:95762CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:95887CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-93491CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2536891CNA: redhat · issue-tracking, x_refsource_REDHAT
- https://github.com/netty/netty/releases/tag/netty-4.1.138.FinalCNA: redhat
- https://github.com/netty/netty/releases/tag/netty-4.2.18.FinalCNA: redhat
- https://access.redhat.com/errata/RHSA-2026:69440[email protected]
- https://access.redhat.com/errata/RHSA-2026:69470[email protected]
- https://access.redhat.com/errata/RHSA-2026:70257[email protected]
- https://access.redhat.com/errata/RHSA-2026:83612[email protected]
- https://access.redhat.com/errata/RHSA-2026:95760[email protected]
- https://access.redhat.com/errata/RHSA-2026:95761[email protected]
- https://access.redhat.com/security/cve/CVE-2026-93491[email protected]
- https://bugzilla.redhat.com/show_bug.cgi?id=2536891[email protected]
- https://github.com/netty/netty/releases/tag/netty-4.1.138.Final[email protected]
- https://github.com/netty/netty/releases/tag/netty-4.2.18.Final[email protected]
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