| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| A flaw was found in Netty's HTTP/2 stack. This vulnerability allows a remote attacker to inject prohibited characters, such as NUL, Line Feed, and Carriage Return, into HTTP/2 header field values due to insufficient validation. When these values cross an HTTP/2 to HTTP/1.1 translation boundary, they can be exploited for request smuggling, header injection, or response splitting. This could lead to unauthorized access, data manipulation, or other security bypasses. |
| Netty split Transfer-Encoding fields bypass final-chunked validation and enable request smuggling |
| HTTP/1 absolute-form Host mismatch is translated to HTTP/2 :authority, overriding the request-target authority |
| HTTP/2 and HTTP/3 Extended CONNECT requests are downgraded as regular CONNECT requests |
| Netty netty-codec-smtp — SMTP command-name field is not CRLF-validated (incomplete fix of CVE-2025-59419) |
| HTTP/1 authority-form CONNECT is translated to malformed HTTP/2 CONNECT with Host-controlled :authority |
| ### Summary
Netty skips strict chunk size line validation when the line has no chunk extension (`;`), so a chunk size line containing an embedded bare CR (e.g. `0\rX`) is accepted instead of rejected, enabling HTTP request smuggling.
### Details
`io.netty.handler.codec.http.HttpObjectDecoder#checkChunkExtensions` only runs the strict validator `HttpChunkLineValidatingByteProcessor` when a `;` is present:
```java
int extensionsStart = line.bytesBefore((byte) ';');
if (extensionsStart == -1) {
return;
}
```
According to RFC 9112 https://datatracker.ietf.org/doc/html/rfc9112#appendix-A
`chunk-size = 1*HEXDIG`
### PoC
```java
@Test
public void test() {
String requestStr = "POST / HTTP/1.1\r\n" +
"Host: localhost\r\n" +
"Transfer-Encoding: chunked\r\n\r\n" +
"0\rX\r\n" +
"\r\n" +
"GET /smuggled HTTP/1.1\r\n" +
"Host: localhost\r\n" +
"Content-Length: 0\r\n" +
"\r\n";
EmbeddedChannel channel = new EmbeddedChannel(new HttpRequestDecoder());
assertTrue(channel.writeInbound(Unpooled.copiedBuffer(requestStr, Ch |
| ### 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 |
| HAProxy PROXY-v2 nested-TLV grandchild ByteBuf reference-count leak (incomplete fix of PR #16881) |
| Unbounded Per-Connection Queue Growth in WebSocketServerExtensionHandler Leads to Denial of Service |
| Missing Extended Key Usage (EKU) check in OCSP Client allows certificate revocation bypass |
| STOMP codec content-length long-to-int truncation causes infinite decode loop DoS |
| ## Summary
`RedisArrayAggregator` recently added `maxElements` and `maxNestedArrayDepth` limits to fix public Redis resource-exhaustion advisories. The limits are independent, but the allocator remains eager: every positive nested RESP array header creates `new ArrayList<RedisMessage>(length)` before any child element exists.
With the default constructor, an attacker can send nested array headers with length `1,000,000` until the default nesting limit of `1024` is reached. This can reserve up to `1,024,000,000` child slots from roughly 12 KB of RESP input. This is backing capacity, not logical list size: `ArrayList(int)` constructs an empty list with the specified initial capacity.
## Technical Details
Current `decodeRedisArrayHeader(...)` checks the two limits independently:
```java
if (header.length() > maxElements) {
throw new CodecException("this codec doesn't support longer length than " + maxElements);
}
if (depths.size() >= maxNestedArrayDepth) {
releaseAndClearDepths();
throw new CodecException("max nested array depth exceeded: " + maxNestedArrayDepth);
}
depths.push(new AggregateState((int) header.length()));
```
`AggregateState` i |
| ### Summary
Netty's fix for CVE-2026-44248 is incomplete. The decoder checks if the MQTT packet's `Remaining Length` exceeds `maxBytesInMessage`, but fails to validate the `Properties Length` against the `Remaining Length`. An attacker can bypass the size limit by sending a small `Remaining Length` but an enormous `Properties Length`. This forces Netty to buffer and parse millions of properties, allowing an unauthenticated remote attacker to trigger excessive memory and CPU consumption, leading to OutOfMemoryError.
### Details
In `io.netty.handler.codec.mqtt.MqttDecoder`, the `decodeProperties()` helper method reads `totalPropertiesLength` and attempts to parse that many bytes. If the buffer lacks the full length, a `Signal` is thrown. The `catch` block inside `decode()` only enforces `maxBytesInMessage` against `bytesRemainingBeforeVariableHeader` (the packet's `Remaining Length`).
By sending a `CONNECT` packet with a small `Remaining Length` but a huge `Properties Length`, the size check passes. `ReplayingDecoder` then buffers data from the network until the huge `Properties Length` is reached, parsing millions of `UserProperty` objects and exhausting CPU and memory.
# |
| Memcache binary codec signed/unsigned type mismatch causes frame desynchronization and response smuggling |
| Unbounded multi-line response accumulation in SmtpResponseDecoder leads to memory-exhaustion DoS |
| A flaw was found in Netty's HTTP/2 HpackEncoder. A remote attacker can exploit this by sending HTTP/2 SETTINGS frames with a very large MAX_HEADER_TABLE_SIZE. This causes the HpackEncoder to store an excessive number of unique headers, leading to increased CPU usage and memory consumption, ultimately resulting in a Denial of Service (DoS). |
| 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. |
| 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. |
| A flaw was found in Netty's `netty-handler-ssl-ocsp` component. A remote attacker can exploit this vulnerability by providing an Online Certificate Status Protocol (OCSP) response that omits the optional `nextUpdate` field. This omission causes the OCSP validation to be silently skipped, leading to applications proceeding with an unvalidated certificate. This can result in a bypass of security controls where certificate validation is expected. |
