Public vulnerability disclosure
CVE-2026-93488
Io.netty/netty-codec-http: netty: denial of service via unbounded concurrent spdy streams
publishedCWE-770
A flaw was found in Netty. SpdySessionHandler accepts an unlimited number of concurrent remote-initiated streams because localConcurrentStreams defaults to Integer.MAX_VALUE and the handler provides no API to change it. A remote peer can open a SPDY connection and send a large number of SYN_STREAM frames with FLAG_FIN=0, causing unbounded heap and direct memory allocation that can lead to JVM OutOfMemoryError and a denial of service.
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-2026-93488CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2536887CNA: 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-2026-93488[email protected]
- https://bugzilla.redhat.com/show_bug.cgi?id=2536887[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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