RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7, Admin-only atom exhaustion: PUT /api/users tags list. settags/2 maps rabbitdatacoercion:toatom/1 over the user's tags list. The 20 MB management body limit fits ~3-4M short tag strings. An administrator can crash the node in a single request by creating a user (or importing definitions) with ~1M unique tag administrator. This issue is fixed in versions 4.0.22 and 4.1.14 and 4.2.7.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-400"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67226.json",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.0.22"
},
{
"introduced": "4.1.0"
},
{
"fixed": "4.1.14"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
}
]
}
]
}{
"extracted_events": [
{
"range": [
{
"introduced": "4.2.0"
},
{
"fixed": "4.2.7"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "86601c5a6d1c7e41060e3dbd165c88bdc91266ee"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v4.2.7",
"range": [
{
"fixed": "b15fd2a3e5465cb6ed403d5a774ef61b1a391b89"
}
],
"source": "REFERENCES_TAG"
}
]
}