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Fencer Intel
high 7.4

CVE-2026-59986 json

rabbitmq-c: amqp_decode_bytes size_t integer overflow bypasses bounds check on 32-bit (OOB read)

published 4mo ago modified yesterday also EUVD-2026-121280 , GHSA-jgjf-7fwf-f3c7

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository alanxz/rabbitmq-c. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to version 0.17.0, the bounds check (*offset = o + len) <= encoded.len overflows when o + len > SIZE_MAX on 32-bit systems. len is a uint32_t read from the AMQP wire as a BYTES/UTF8 field length. The overflow wraps the check to a small value that passes, producing a decoded amqp_bytes_t with a multi-GB .len pointing into a small frame buffer. This results in an out-of-bounds read of up to ~4GB of process memory on 32-bit systems (ARM, MIPS, x86 ILP32, embedded IoT AMQP clients). Enabling information disclosure or denial of service. Not exploitable on 64-bit systems where size_t is 64-bit. This issue has been patched in version 0.17.0.

Patch / fix

  • librabbitmq Debian 12 0.11.0-1+deb12u3
  • librabbitmq Debian 13 0.15.0-1+deb13u2
  • librabbitmq Debian 14 0.17.0-1

debian advisories DEBIAN-CVE-2026-59986

  • librabbitmq Ubuntu 22.04 LTS 0.10.0-1ubuntu2.2
  • librabbitmq Ubuntu 24.04 LTS 0.11.0-1ubuntu0.2
  • librabbitmq Ubuntu 26.04 LTS 0.15.0-1ubuntu0.26.04.2
  • librabbitmq Ubuntu Pro 14.04 LTS 0.4.1-1ubuntu0.1~esm2
  • librabbitmq Ubuntu Pro 16.04 LTS 0.7.1-1ubuntu0.2+esm1
  • librabbitmq Ubuntu Pro 18.04 LTS 0.8.0-1ubuntu0.18.04.2+esm1
  • librabbitmq Ubuntu Pro 20.04 LTS 0.10.0-1ubuntu0.20.04.1~esm1

ubuntu advisories UBUNTU-CVE-2026-59986

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2026-59986 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
yesterday

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/alanxz/rabbitmq-c/security/advisories/GHSA-jgjf-7fwf-f3c7 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products

  • alanxz rabbitmq-c

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of alanxz/rabbitmq-c published their own advisory on GitHub. Reviewed sources take precedence over it.