Malformed Valkey Cluster bus message can lead to Remote DoS
Valkey is a distributed key-value database. Prior to versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12, a malicious actor with access to the Valkey clusterbus port can send an invalid packet that may cause an out bound read, which might result in the system crashing. The Valkey clusterbus packet processing code does not validate that a clusterbus ping extension packet is located within buffer of the clusterbus packet before attempting to read it. Versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12 fix the issue. As an additional mitigation, don't expose the cluster bus connection directly to end users, and protect the connection with its own network ACLs.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-21863
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 04:01 UTC · Revision 1
Source evidence
Malformed Valkey Cluster bus message can lead to Remote DoS
core-osv · Original sourcePublished 23 Feb 2026, 19:41 UTC
Valkey is a distributed key-value database. Prior to versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12, a malicious actor with access to the Valkey clusterbus port can send an invalid packet that may cause an out bound read, which might result in the system crashing. The Valkey clusterbus packet processing code does not validate that a clusterbus ping extension packet is located within buffer of the clusterbus packet before attempting to read it. Versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12 fix the issue. As an additional mitigation, don't expose the cluster bus connection directly to end users, and protect the connection with its own network ACLs.
osv:CVE-2026-21863
Complete source record
{
"id": "9734da7c2631d6cefc43ae4e19f3498c8ca161d281ed8009f66e152f0bba7d60",
"url": "https://osv.dev/vulnerability/CVE-2026-21863",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Malformed Valkey Cluster bus message can lead to Remote DoS",
"summary": "Valkey is a distributed key-value database. Prior to versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12, a malicious actor with access to the Valkey clusterbus port can send an invalid packet that may cause an out bound read, which might result in the system crashing. The Valkey clusterbus packet processing code does not validate that a clusterbus ping extension packet is located within buffer of the clusterbus packet before attempting to read it. Versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12 fix the issue. As an additional mitigation, don't expose the cluster bus connection directly to end users, and protect the connection with its own network ACLs.",
"evidence": "osv:CVE-2026-21863",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-21863",
"aliases": [
"BIT-valkey-2026-21863",
"CVE-2026-21863",
"GHSA-c677-q3wr-gggq"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/valkey-io/valkey",
"type": "GIT",
"events": [
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"introduced": "0"
},
{
"fixed": "7b696d1a4f8b2a5b5393dba7c6706f7aa8599013"
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{
"introduced": "2b5c7a0dbd61fd4281ef6166b7d119ba7fe7368c"
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{
"fixed": "d77c7aaf01d273d2480aeabf5ed578aa0133d9a1"
},
{
"introduced": "67c8683792fc9ab7e295f833478eca180c5e4691"
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{
"fixed": "19b07dfcbb75b14a1ed1b0a48cb8a0efcc81d563"
},
{
"introduced": "5018b12b0de2d2322a1bbf6b041c43740587c0f2"
},
{
"fixed": "1ac4cfe4c877a6cb8cb2e28fa7094055ac06f64b"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "7.2.12"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "8.0.0"
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{
"fixed": "8.0.7"
}
],
"source": "CPE_RANGE"
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{
"cpe": "cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "8.1.0"
},
{
"fixed": "8.1.6"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "9.0.0"
},
{
"fixed": "9.0.2"
}
],
"source": "CPE_RANGE"
}
]
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}
],
"versions": [
"8.1.5",
"9.0.1",
"9.0.0",
"7.2.11",
"8.0.6",
"8.1.4",
"7.2.10",
"8.0.5",
"8.0.4",
"8.1.3",
"8.0.3",
"8.1.2",
"7.2.9",
"8.1.1",
"8.1.0",
"7.2.8",
"8.0.2",
"7.2.7",
"8.0.1",
"8.0.0",
"7.2.6",
"7.2.5",
"7.2.5-rc1",
"7.2.4-rc1",
"7.2.4"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21863.json"
}
}
],
"modified": "2026-10-28T02:30:25.692549383Z",
"provider": "osv",
"references": [
"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21863.json",
"https://access.redhat.com/errata/RHSA-2026:3443",
"https://access.redhat.com/errata/RHSA-2026:3507",
"https://access.redhat.com/errata/RHSA-2026:5445",
"https://access.redhat.com/errata/RHSA-2026:8753",
"https://access.redhat.com/security/cve/CVE-2026-21863",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21863.json",
"https://github.com/valkey-io/valkey/security/advisories/GHSA-c677-q3wr-gggq",
"https://nvd.nist.gov/vuln/detail/CVE-2026-21863",
"https://bugzilla.redhat.com/show_bug.cgi?id=2442026"
],
"provider_metadata": {
"cwe_ids": [
"CWE-125"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21863.json"
}
},
"related_cves": [
{
"value": "CVE-2026-21863",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 492347,
"published_at": "2026-02-23T19:41:28.783+00:00"
}