CVE-2026-93565
Io.netty/netty-codec-http: netty rtspdecoder method-token smuggling via trailing control byte
What happened?
A flaw was found in Netty RtspDecoder. The `RtspMethods.valueOf()` function incorrectly strips trailing control bytes from method tokens in Real-Time Streaming Protocol (RTSP) requests. A remote attacker can exploit this by sending a specially crafted RTSP request, leading to method-token smuggling. This vulnerability allows an attacker to bypass method-based access controls and can also be used to launder malicious requests through Netty-based RTSP proxies, making them appear legitimate to backend systems.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| io.netty/netty-codec-httpRed Hat | unaffected: 4.1.138.Final-redhat-00001 to < * | See vendor advisory |
| netty-codec-httpRed Hat | Default status: unaffected | See vendor advisory |
| keycloak-rhel9-containerRed Hat | unaffected: 26.4-29 to < * | See vendor advisory |
| keycloak-rhel9-operator-bundle-containerRed Hat | unaffected: 26.4.17-2 to < * | See vendor advisory |
| keycloak-rhel9-operator-containerRed Hat | unaffected: 26.4-30 to < * | See vendor advisory |
| netty-codec-httpRed Hat | Default status: unaffected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: unaffected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: unaffected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: unaffected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: affected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: affected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: affected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: affected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: affected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: affected | See vendor advisory |
| netty-codec-httpRed Hat | Default status: unknown | See vendor advisory |
| netty-codec-httpRed Hat | Default status: unknown | See vendor advisory |
| netty-codec-httpRed Hat | Default status: affected | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.
Sources and remediation references
- https://www.cve.org/CVERecord?id=CVE-2026-93565
- https://access.redhat.com/errata/RHSA-2026:69440
- https://access.redhat.com/errata/RHSA-2026:69470
- https://access.redhat.com/errata/RHSA-2026:70257
- https://access.redhat.com/errata/RHSA-2026:83612
- https://access.redhat.com/errata/RHSA-2026:95760
- https://access.redhat.com/errata/RHSA-2026:95761
- https://access.redhat.com/errata/RHSA-2026:95887
- https://access.redhat.com/security/cve/CVE-2026-93565
- https://bugzilla.redhat.com/show_bug.cgi?id=2536952