rabbitmq-c: Heap buffer overflow in AMQP login handshake via undersized connection.tune.frame_max (CVE-2026-44236) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-44236

rabbitmq-c: Heap buffer overflow in AMQP login handshake via undersized connection.tune.frame_max

Answer in brief

CVE-2026-44236 records a Unknown severity vulnerability in rabbitmq-c: Heap buffer overflow in AMQP login handshake via undersized connection.tune.frame_max. The current sources do not mark it as known exploited. The current feed maps alanxz/rabbitmq-c (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps alanxz/rabbitmq-c (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
alanxz/rabbitmq-cgeneric	< 0.16.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for alanxz/rabbitmq-c.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to 0.16.0, a malicious AMQP server can send an undersized connection.tune.frame_max value during amqp_login(), and rabbitmq-c accepts the value in amqp_login_inner() in librabbitmq/amqp_socket.c. amqp_tune_connection() in librabbitmq/amqp_connection.c uses frame_max to reallocate the outbound buffer without enforcing AMQP_FRAME_MIN_SIZE. Immediate serialization of connection.tune-ok through amqp_frame_to_bytes() writes beyond the undersized heap allocation, causing memory corruption and likely denial of service. An on-path attacker can also trigger the flaw against plaintext AMQP traffic. Code execution is theoretically possible but was not demonstrated. This issue is fixed in version 0.16.0.

Quoted source text, attributed separately from HOL analysis.