jackson-databind: PolymorphicTypeValidator bypass via generic type arguments and array element types allows arbitrary class instantiation (incomplete fix for CVE-2026-54512)

jackson-databind validates the outer class of a class-name type ID but accepts attacker-selected classes inside its generic arguments, even when those classes violate the declared type or would be rejected as direct type IDs. This bypasses the generic-argument validation added for CVE-2026-54512 (GHSA-j3rv-43j4-c7qm), of which this is an incomplete fix. DatabindContext._resolveAndValidateGeneric() checks the outer class against the declared base type and then passes each argument from the type ID to _validateTypeParameter(), which validates the argument against the outer base type rather than enforcing its corresponding declared generic binding. It also invokes validators with arguments that have not passed the subtype check those validators expect. Under the default DefaultBaseTypeLimitingValidator this accepts an unrelated class inside a generic subtype even when the same class is rejected as a direct type ID. Where an allowIfBaseType(...) rule approves the outer type, Jackson substitutes LaissezFaireSubTypeValidator, so the configured validator no longer restricts the embedded arguments. The element type of a plain array type ID such as [Lpkg.Gadget; is likewise left unvalidated once the array's base type is approved. Affected paths include annotation-based class-name polymorphism with a default Jackson 3.x JsonMapper, configured default typing in both Jackson 2.x and 3.x, and integrations that expose that default typing. The default-validator case requires no application-authored validator: with @JsonTypeInfo(use = Id.CLASS), a direct gadget type ID is rejected as "Not a subtype", while a type ID naming a generic wrapper around the same gadget is accepted and deserialized, including attacker-supplied bean properties. Where class-name default typing permits Map, a property declared as Map<String,String> accepts HashMap<FileSystemXmlApplicationContext,String>; map-key discovery then passes the attacker-controlled JSON property name to the selected class's one-string constructor. With Spring on the classpath and attacker-controlled XML the application can load, that constructor loads the XML and invokes ProcessBuilder.start() under the application account, giving arbitrary command execution. This issue affects com.fasterxml.jackson.core:jackson-databind from 2.10.0 and tools.jackson.core:jackson-databind from 3.0.0. Releases before 2.10.0 are not affected, because PolymorphicTypeValidator was introduced in jackson-databind 2.10.0.

Io.netty/netty-codec-http2: netty: http/2 header field values are not validated by default (cr/lf/nul passthrough)

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.

Io.netty/netty-codec-http2: netty: http/2 hpackencoder dos with large table size

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).

Io.netty/netty-codec-http: netty: http request smuggling due to control characters in the chunk-size line

A flaw was found in Netty. A remote attacker could exploit this by sending a specially crafted HTTP request that includes control characters within the chunk-size line. This bypasses the intended strict validation, allowing the attacker to inject arbitrary HTTP requests. This vulnerability can lead to HTTP request smuggling, potentially resulting in information disclosure or other unauthorized actions.

Io.netty/netty-codec-http: netty: incomplete validation of malformed transfer-encoding allows http request smuggling

A flaw was found in Netty's HTTP/1 decoder. Incomplete validation of malformed Transfer-Encoding headers allows a remote attacker to perform HTTP request smuggling. By sending specially crafted HTTP requests, an attacker can inject arbitrary HTTP requests, potentially bypassing security controls or accessing unauthorized resources.

Io.netty/netty-codec-http: netty rtspdecoder method-token smuggling via trailing control byte

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.

Io.netty/netty-codec-haproxy: netty: haproxy proxy-v2 nested-tlv grandchild bytebuf reference-count leak (incomplete fix of pr #16881)

A flaw was found in Netty. A reference-count leak in the HAProxy PROXY-v2 message decoder allows a remote, unauthenticated attacker to send specially crafted PROXY-protocol v2 headers. This can lead to memory exhaustion, resulting in a Denial of Service (DoS) for the affected system.

Io.netty/netty-codec-http: netty: unbounded per-connection queue growth in websocketserverextensionhandler leads to denial of service

A flaw was found in Netty's WebSocketServerExtensionHandler. A remote, unauthenticated attacker can exploit this vulnerability by using HTTP/1.1 pipelining to send requests faster than the application can respond. This leads to an unbounded growth of a per-connection queue, consuming excessive memory. Eventually, this can cause the Java Virtual Machine (JVM) to exhaust its heap, resulting in a Denial of Service (DoS) for the affected server.

Io.netty/netty-codec-mqtt: netty: resource exhaustion in mqttdecoder

A flaw was found in Netty's MqttDecoder. An unauthenticated remote attacker can exploit this vulnerability by sending a specially crafted MQTT CONNECT packet. The decoder fails to properly validate the 'Properties Length' against the 'Remaining Length', allowing an attacker to bypass size limits. This leads to excessive memory and CPU consumption, resulting in a denial of service (DoS) due to an OutOfMemoryError.

Io.netty/netty-codec-stomp: netty: stomp codec content-length long-to-int truncation causes infinite decode loop dos

A flaw was found in the Netty STOMP codec. A remote attacker could send a specially crafted STOMP frame with a content-length header exceeding the maximum integer value. This integer truncation vulnerability could lead to an infinite decode loop, causing a Denial of Service (DoS) by exhausting memory and CPU resources.

Io.netty/netty-codec-stomp: netty: bytebuf leak in stompsubframedecoder when a frame body is never terminated

A flaw was found in Netty's StompSubframeDecoder component. A remote attacker can exploit this vulnerability by sending a specially crafted STOMP frame body without its terminating null byte. This causes the decoder to allocate a ByteBuf (a buffer for bytes) that is never released, leading to a permanent memory leak. Over time, this uncontrolled memory consumption can result in a Denial of Service (DoS) for the application using the affected STOMP codec.

Io.netty/netty-codec-memcache: netty: memcache binary codec signed/unsigned type mismatch causes frame desynchronization and response smuggling

A flaw was found in io.netty/netty-codec-memcache. The Memcache binary protocol codec incorrectly reads `keyLength` and `extrasLength` as signed Java types instead of unsigned, as specified by the protocol. A malicious Memcache server can exploit this type mismatch by sending a specially crafted response. This can lead to frame desynchronization and response smuggling, where one client's data may be inadvertently exposed to another client's response stream in proxy or cache environments.

Io.netty/netty-handler-ssl-ocsp: netty: missing extended key usage (eku) check in ocsp client allows certificate revocation bypass

A flaw was found in Netty's Online Certificate Status Protocol (OCSP) Client. The client fails to verify the 'id-kp-OCSPSigning' Extended Key Usage (EKU) in OCSP responder certificates. A remote attacker, holding any valid certificate issued by the same Certificate Authority (CA), can exploit this by forging 'GOOD' OCSP responses for revoked certificates. This bypasses certificate revocation checks, allowing applications using Netty's OCSP Client to accept certificates that should have been revoked, leading to an authorization bypass.

Io.netty/netty-codec-smtp: netty: unbounded multi-line response accumulation in smtpresponsedecoder leads to memory-exhaustion dos

A flaw was found in Netty's `SmtpResponseDecoder` component. A remote attacker, acting as a malicious or man-in-the-middle (MITM) SMTP server, could exploit this by sending a specially crafted, unbounded multi-line SMTP response without a terminator. This vulnerability leads to unbounded memory accumulation within the client's Java Virtual Machine (JVM) heap, causing an `OutOfMemoryError` and a denial of service (DoS) due to a process crash.

Vulnerability in the Oracle VM VirtualBox product of Oracle Virtualization (component: Core). The supported version that is affected is 7.2.16. Easily exploitable vulnerability allows high privileged attacker with logon to the infrastructure where Oracle VM VirtualBox executes to compromise Oracle VM VirtualBox. While the vulnerability is in Oracle VM VirtualBox, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle VM VirtualBox. CVSS 3.1 Base Score 6.0 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H).