RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.8 and 4.3.2, get_auth_mechanism/1 used term_to_binary/1 on the strict_auth_mechanism or preferred_auth_mechanism atom when clearing the corresponding cookie, producing a non-ASCII cookie name that violates RFC 6265 and can prevent the browser from deleting the preference. The issue is not directly exploitable for code execution or data exfiltration; its security relevance is limited to stale authentication-mechanism preferences persisting across logout and login cycles. This issue is fixed in versions 4.2.8 and 4.3.2.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-20"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67234.json"
}