What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-17 · updated 2026-09-24
• Weakness: CWE-122

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.

Affected products

• alanxz rabbitmq-c: before 0.16.0

References

• https://github.com/alanxz/rabbitmq-c/commit/4777d0b5c58cb02966a04a85832436bd66ed5d1f
• https://github.com/alanxz/rabbitmq-c/pull/879
• https://github.com/alanxz/rabbitmq-c/releases/tag/v0.16.0
• https://github.com/alanxz/rabbitmq-c/security/advisories/GHSA-jh48-qjf5-fx5v
• https://github.com/alanxz/rabbitmq-c/security/advisories/GHSA-jh48-qjf5-fx5v

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