RabbitMQ amqp091-go: Protocol Desynchronization and Frame Injection via Integer Overflow in readLongstr

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readLongstr in read.go returns an empty string and a nil error when a declared AMQP longstr length exceeds 0x7FFFFFFF instead of returning ErrSyntax. The function leaves the declared field bytes unread, while readTable treats the operation as successful and continues parsing from the wrong offset. A malicious or compromised broker can provide an oversized longstr in a table field and desynchronize subsequent AMQP parsing, causing attacker-controlled trailing bytes to be interpreted as later fields or frames and disrupting connection integrity and availability. This issue is fixed in version 1.13.0.

Source published

16 Sep 2026 14:45:48 UTC

Source modified

16 Sep 2026 18:35:32 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 9.5 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readLongstr in read.go returns an empty string and a nil error when a declared AMQP longstr length exceeds 0x7FFFFFFF instead of returning ErrSyntax. The function leaves the declared field bytes unread, while readTable treats the operation as successful and continues parsing from the wrong offset. A malicious or compromised broker can provide an oversized longstr in a table field and desynchronize subsequent AMQP parsing, causing attacker-controlled trailing bytes to be interpreted as later fields or frames and disrupting connection integrity and availability. This issue is fixed in version 1.13.0.

Source published

Sep 16, 2026, 2:45:48 PM (timezone not stated)

Source modified

Sep 16, 2026, 6:35:32 PM (timezone not stated)

Observed here

11 Nov 2026 16:08:47 UTC

Source terms

ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 9.5 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readLongstr in read.go returns an empty string and a nil error when a declared AMQP longstr length exceeds 0x7FFFFFFF instead of returning ErrSyntax. The function leaves the declared field bytes unread, while readTable treats the operation as successful and continues parsing from the wrong offset. A malicious or compromised broker can provide an oversized longstr in a table field and desynchronize subsequent AMQP parsing, causing attacker-controlled trailing bytes to be interpreted as later fields or frames and disrupting connection integrity and availability. This issue is fixed in version 1.13.0.

Source published

16 Sep 2026 15:17:50 UTC

Source modified

23 Sep 2026 18:19:19 UTC

Observed here

25 Oct 2026 16:19:04 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 9.5 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

**Summary** A critical stream desynchronization vulnerability has been identified in the AMQP wire-protocol parser. When parsing a long string (`readLongstr`) within a table field, providing a length that exceeds the maximum signed 32-bit integer (`2^31 - 1`, or roughly `2.1` GiB) triggers an improper error-handling condition. The parser abruptly aborts the read and returns a success status (`"",nil`) without consuming the specified bytes from the underlying network buffer. This causes all subsequent read operations to become misaligned. The parser interprets arbitrary offsets within the remaining payload bytes as valid AMQP frame headers, leading to potential Remote Code Execution (RCE), data injection, or complete connection hijacking. **Vulnerability Details** The vulnerability exists within the bounds-checking logic of the readLongstr function: ```go // read.go:113-114 — silent no-op return, bytes left in stream if length > (^uint32(0) >> 1) { return // returns "", nil, does NOT consume `length` bytes } ``` When `length` evaluates to a value greater than `0x7FFFFFFF`: 1. The function executes a silent `return` statement. 2. Because Go utilizes named or zero-value initialization for unassigned return registers, this yields `"", nil` (indicating a successful read of an empty string). 3. The Critical Failure: The reader's cursor is not advanced by `length` bytes. The malformed payload remains sitting in the TCP/buffer stream. **Impact** As `readTable` continues iterating over the stream under the assumption that the string was successfully parsed, the byte alignment is entirely broken. - Parser Desynchronization: Future AMQP frame headers are read from arbitrary offsets inside the attacker-controlled message payload. - Payload Reinterpretation: A malicious actor can carefully craft the trailing bytes of the initial payload to perfectly mimic valid AMQP frames (e.g., `connection.close`, `channel.open`, or message publishing frames), forcing the client/server to execute unintended actions.

Source published

17 Sep 2026 17:04:25 UTC

Source modified

1 Oct 2026 20:56:08 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Publisher rating · CRITICAL

RabbitMQ amqp091-go: Protocol Desynchronization and Frame Injection via Integer Overflow in readLongstr in github.com/rabbitmq/amqp091-go

Source published

1 Oct 2026 20:23:56 UTC

Source modified

1 Oct 2026 20:45:11 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.