Buffer overflow in Alanxz Rabbitmq-C

CVE-2026-44236

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H.

EPSS exploit prediction

EPSS: 0.004 (34.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-44236: held from 0.005 to 0.004.

EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44236?
CVE-2026-44236 is a high-severity vulnerability in Alanxz Rabbitmq-C, classified under Heap-based Buffer Overflow. CVSS score: 7.1/10. Published 2026-09-17.
How severe is CVE-2026-44236?
High severity. CVSS v3 base score is 7.1 out of 10.