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NVD / CVE Program· CNA GitHub_M

CVE-2026-44838: RabbitMQ MQTT Topic Permission Authorization Bypass

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: rabbitmq rabbitmq-server 4.2.4.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to rabbitmq rabbitmq-server 4.2.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

RabbitMQ is a messaging and streaming broker. From 4.2.0 to before 4.2.4, RabbitMQ's MQTT plugin allows for topic-level authorization using regular expressions with variable substitution. Administrators can create patterns such as ^{client_id}-sensors$ to restrict user access to topics that include their client ID. However, the client_id is provided by the user in the MQTT CONNECT packet and is inserted into the regex pattern without escaping special regex characters. This flaw enables an authenticated MQTT user to inject regex operators to bypass authorization. This vulnerability is fixed in 4.2.4 and 4.3.0.

MediumCVSS 5.3 · v4.0—No exploit Fix available
Published
May 27, 2026
Updated
Oct 26, 2026
EPSS
0.2% · 10th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
5.3
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-44838

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
broadcomrabbitmq server

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • broadcom rabbitmq server4.2.0 and later · before 4.2.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • rabbitmq rabbitmq-server

    • >= 4.2.0, < 4.2.4affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Red Hat:hummingbird:1rabbitmq-server4.2before 0:4.2.9-0.1.hum10:4.2.9-0.1.hum1
Red Hat:hummingbird:1rabbitmq-server4.3before 0:4.3.4-0.1.hum10:4.3.4-0.1.hum1

Same product

broadcom: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-57216RabbitMQ: AMQP 1.0, AMQP 0-9-1, Stream Protocol loopback enforcement can lead to remote guest sessions due to listener-address loopback checks
    40Plan
  • CVE-2026-57211RabbitMQ: UNC SSRF affecting the management UI on Windows
    40Plan
  • CVE-2016-9877An issue was discovered in Pivotal RabbitMQ 3.x before 3.5.8 and 3.6.x before 3.6.6 and RabbitMQ for PCF 1.5.x before 1.5.20, 1.6.x before 1
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2022-31008Oct 6, 2022 · Predictable credential obfuscation seed value used in rabbitmq-server
    30Monitor
  • ← EarlierCVE-2025-50200Jun 19, 2025 · RabbitMQ Node can log Basic Auth header from an HTTP request
    26Monitor
  • Later →CVE-2026-44839May 27, 2026 · RabbitMQ: Unsanitized vhost names allow for XSS in management UI
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
rabbitmq rabbitmq-server4.2.4 · descriptionVendor (CNA)
red hat:rabbitmq-server4.20:4.2.9-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:rabbitmq-server4.30:4.3.4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-5721544 days apartRabbitMQ: Direct-reply-to binding persistence can lead to unauthorized reply-channel injection and persistent phantom
    28Monitor
  • CVE-2026-5721744 days apartRabbitMQ: Topic authorization can lead to cross-tenant routing-key bypass
    28Monitor
  • CVE-2026-67411121 days apartRabbitMQ: Web MQTT with PROXY Protocol enabled: a loopback-only user permission bypass
    24Monitor
  • CVE-2026-5721844 days apartRabbitMQ: AMQP 0-9-1 in combination with OAuth 2: consumer persistence can lead to post-revocation message disclosure
    19Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
X

Weakness class (CWE)

CWE-863 · Incorrect Authorization

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records