CVE-2026-93565
Io.netty/netty-codec-http: netty rtspdecoder method-token smuggling via trailing control byte
Description
### Summary `RtspMethods.valueOf()` silently strips trailing control bytes (any character with code point <= 0x20, the full range that `String.trim()` removes) before performing a cache lookup against its ten pre-populated method constants. A wire-delivered RTSP request whose method token ends with a trailing control byte — for example `PLAY\x00` or `PLAY\r`, immediately before the separating space — is decoded by `RtspDecoder` as a fully successful PLAY request, with `decoderResult().isSuccess() == true and request.method() == RtspMethods.PLAY` (same object reference as the cached singleton). The application layer cannot distinguish this from a clean `PLAY` request. This is the same root cause as #16723 and #16971, in a sibling that those fixes did not reach. The fix for `HttpMethod` hardened `HttpMethod.valueOf()` directly, but `RtspMethods.valueOf()` has its own independent `checkNonEmptyAfterTrim()` call that runs before the cache lookup — meaning a trailing-control-byte token hits the cache before the hardened `HttpMethod` constructor ever sees it. ### Reproduction Minimal wire-level reproduction Send the following raw bytes to any Netty-based RTSP server using R
INFO
Published Date :
Sept. 18, 2026, 3:17 p.m.
Last Modified :
Sept. 18, 2026, 3:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-93565
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Apply available software updates to the affected system.
- Verify that RtspMethods.valueOf() handles trailing control bytes correctly.
- Review security configurations for RTSP handling.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-93565.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-93565 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2536952 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93565 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-93565
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-93565 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-93565 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added Description ### Summary `RtspMethods.valueOf()` silently strips trailing control bytes (any character with code point <= 0x20, the full range that `String.trim()` removes) before performing a cache lookup against its ten pre-populated method constants. A wire-delivered RTSP request whose method token ends with a trailing control byte — for example `PLAY\x00` or `PLAY\r`, immediately before the separating space — is decoded by `RtspDecoder` as a fully successful PLAY request, with `decoderResult().isSuccess() == true and request.method() == RtspMethods.PLAY` (same object reference as the cached singleton). The application layer cannot distinguish this from a clean `PLAY` request. This is the same root cause as #16723 and #16971, in a sibling that those fixes did not reach. The fix for `HttpMethod` hardened `HttpMethod.valueOf()` directly, but `RtspMethods.valueOf()` has its own independent `checkNonEmptyAfterTrim()` call that runs before the cache lookup — meaning a trailing-control-byte token hits the cache before the hardened `HttpMethod` constructor ever sees it. ### Reproduction Minimal wire-level reproduction Send the following raw bytes to any Netty-based RTSP server using R Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-1035 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93565.json">CVE-2026-93565</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-93565 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2536952