CVE-2026-77412

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readField in read.go reads the length of an AMQP byte-array field with type tag x into a signed int32 and passes the value directly to make when allocating the field buffer. A malicious or compromised broker can encode a value such as 0xFFFFFFFF, which becomes -1 and causes a len out of range runtime panic. The panic escapes the network reader goroutine and terminates the client process, including during connection.start server properties or message header table parsing. This issue is fixed in version 1.13.0.

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readField in read.go reads the length of an AMQP byte-array field with type tag x into a signed int32 and passes the value directly to make when allocating the field buffer. A malicious or compromised broker can encode a value such as 0xFFFFFFFF, which becomes -1 and causes a len out of range runtime panic. The panic escapes the network reader goroutine and terminates the client process, including during connection.start server properties or message header table parsing. This issue is fixed in version 1.13.0.

Summary A vulnerability in the readField function allows a malicious or compromised AMQP server to trigger an unhandled runtime panic in the client application, leading to an immediate crash of the entire process.

Details When parsing incoming AMQP frames, the readField function processes byte-array fields (type tag 'x') by reading a 32-bit big-endian integer to determine the length of the data payload.

// read.go:253-263
case 'x':
    var len int32
    if err = binary.Read(r, binary.BigEndian, &len); err != nil {
        return nil, err
    }
    value := make([]byte, len)  // PANICS if len < 0

If a server transmits a length value of 0xFFFFFFFF, it is interpreted by the client as a signed 32-bit integer with a value of -1. Passing a negative integer to Go's built-in make() function for slice allocation triggers an unrecoverable runtime panic (panic: len out of range).

Because the reader goroutine handles network I/O without an explicit recover() wrapper, this panic propagates up to the runtime root, abruptly terminating the host application.

Attack Vector / Exploitation Scenario An attacker capable of spoofing, compromising, or controlling an AMQP broker can exploit this flaw during two primary phases:

1. Connection Establishment: Sending a malicious connection.start handshake frame containing server-properties with an 'x' type field assigned a negative length.
2. Message Delivery: Delivering a message payload where the header table contains a malformed field matching the criteria above.

Impact Availability: High. A single malformed frame can reliably crash the client process, resulting in a persistent Denial of Service (DoS) if the client automatically reconnects and receives the same payload.

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readField in read.go reads the length of an AMQP byte-array field with type tag x into a signed int32 and passes the value directly to make when allocating the field buffer. A malicious or compromised broker can encode a value such as 0xFFFFFFFF, which becomes -1 and causes a len out of range runtime panic. The panic escapes the network reader goroutine and terminates the client process, including during connection.start server properties or message header table parsing. This issue is fixed in version 1.13.0.

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readField in read.go reads the length of an AMQP byte-array field with type tag x into a signed int32 and passes the value directly to make when allocating the field buffer. A malicious or compromised broker can encode a value such as 0xFFFFFFFF, which becomes -1 and causes a len out of range runtime panic. The panic escapes the network reader goroutine and terminates the client process, including during connection.start server properties or message header table parsing. This issue is fixed in version 1.13.0.

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readField in read.go reads the length of an AMQP byte-array field with type tag x into a signed int32 and passes the value directly to make when allocating the field buffer. A malicious or compromised broker can encode a value such as 0xFFFFFFFF, which becomes -1 and causes a len out of range runtime panic. The panic escapes the network reader goroutine and terminates the client process, including during connection.start server properties or message header table parsing. This issue is fixed in version 1.13.0.