CVE-2026-66071

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Source
https://cve.org/CVERecord?id=CVE-2026-66071
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66071.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-66071
Aliases
  • GHSA-89p2-f5cv-x5cg
Downstream
Published
2026-09-25T16:11:07Z
Modified
2026-09-26T03:45:25Z
Severity
  • 6.0 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
RabbitMQ: Atom exhaustion: OAuth2 JWT tag: scope values
Details

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1, Atom exhaustion: OAuth2 JWT tag: scope values. extractscopes/1 parses scopes of the form .tag: and calls rabbitdatacoercion:toatom() to convert to a tag atom. The token signature is verified first, so the attacker cannot forge scopes , but in IdP configurations where scope content is user-influenced, each login with a novel tag value leaks one In deployments where users can influence the scopes included in their IdP-issued JWT rabbitmqauthbackendoauth2 enabled IdP permits attacker-influenced scope values in signed tokens. This issue is fixed in versions 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-400"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66071.json",
    "unresolved_ranges":  [
        {
            "extracted_events":  [
                {
                    "introduced":  "3.13.0"
                },
                {
                    "fixed":  "3.13.15"
                },
                {
                    "introduced":  "4.0.0"
                },
                {
                    "fixed":  "4.0.22"
                },
                {
                    "introduced":  "4.1.0"
                },
                {
                    "fixed":  "4.1.11"
                }
            ],
            "source":  "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/rabbitmq/rabbitmq-server

Affected ranges

Type
GIT
Repo
https://github.com/rabbitmq/rabbitmq-server
Events
Introduced
95c501fbad76c66156346cf364d158d6e30aa4d9
Fixed
8a56c37f099a7bf609a555de3f0ff8ed23964d20
Introduced
1929eeadf9b2bac12c5434fb56884ef27370580e
Fixed
49decca35e59d2cb774e5abd76412cee721308a5
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "4.2.0"
        },
        {
            "fixed":  "4.2.6"
        },
        {
            "introduced":  "4.3.0"
        },
        {
            "fixed":  "4.3.1"
        }
    ],
    "source":  "AFFECTED_FIELD"
}

Affected versions

v4.*
v4.2.0
v4.2.1
v4.2.2
v4.2.3
v4.2.4
v4.2.5
v4.3.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66071.json"