High
zookeeper — security advisory
The `deleteContainer` opcode (0x14/20) is processed without verifying the caller's ACL permissions, allowing any authenticated client to delete specific znodes in the data tree regardless of the ACL restrictions on the znode or its parent. This opcode is considered internal-only and the official client doesn't have API for it, but a client that can open a plain TCP session on the ZooKeeper client port (2181 by default) - with NO authentication and NO ACL permissions - can delete any empty persistent znode (including regular persistent nodes, container nodes, and TTL nodes) by issuing the raw protocol OpCode deleteContainer (20). The deleteContainer request path completely skips both the session check and the DELETE ACL check that are enforced by the regular delete (OpCode 2) path. This is an authorization bypass / ACL enforcement bug. This issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6. Users are recommended to upgrade to version 3.9.6 or 3.8.7, which fixes the issue.
- Products
- zookeeper
- Affected versions
- 3.4.10-2, 3.4.10-3, 3.4.13-1, 3.4.13-3, 3.4.13-3build1, 3.4.13-3ubuntu0.1~esm1, 3.4.13-4, 3.4.13-5, 3.4.13-5build1, 3.4.13-5ubuntu0.1, 3.4.13-5ubuntu4, 3.4.13-6ubuntu2, 3.4.13-6ubuntu3, 3.4.13-6ubuntu4, 3.4.13-6ubuntu4.1, 3.4.5+dfsg-1, 3.4.5+dfsg-1ubuntu0.1~esm1, 3.4.5+dfsg-1ubuntu0.1~esm3, 3.4.6-8, 3.4.7-1, 3.4.8-1, 3.4.8-1ubuntu0.1~esm1, 3.4.8-1ubuntu0.1~esm2, 3.8.0-11, 3.9.1-1, 3.9.1-1build1, 3.9.1-1build2, 3.9.3-1build2, 3.9.3-1build3, 3.9.4-1, 3.9.5-1, 3.9.5-2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-79993
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:20 UTC · Revision 1
Source evidence
The `deleteContainer` opcode (0x14/20) is processed without verifying the caller's ACL permissions, allowing any authenticated client to delete specific znodes in the data tree regardless of the ACL restrictions on the znode or its parent. This opcode is considered internal-only and the official client doesn't have API for it, but a client that can open a plain TCP session on the ZooKeeper client port (2181 by default) - with NO authentication and NO ACL permissions - can delete any empty persistent znode (including regular persistent nodes, container nodes, and TTL nodes) by issuing the raw protocol OpCode deleteContainer (20). The deleteContainer request path completely skips both the session check and the DELETE ACL check that are enforced by the regular delete (OpCode 2) path. This is an authorization bypass / ACL enforcement bug. This issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6. Users are recommended to upgrade to version 3.9.6 or 3.8.7, which fixes the issue.
osv:UBUNTU-CVE-2026-79993
zookeeper
Fixed versions: Not specified
zookeeper
Fixed versions: Not specified
zookeeper
Fixed versions: Not specified
zookeeper
Fixed versions: Not specified
zookeeper
Fixed versions: Not specified
zookeeper
Fixed versions: Not specified
zookeeper
Fixed versions: Not specified
zookeeper
Fixed versions: Not specified
Complete source record
{
"id": "5a92072cb2022a6302051058f6760b6fa9cbf4cbcd2cd6dbfa14a48d2fb2a237",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-79993",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-79993",
"summary": "The `deleteContainer` opcode (0x14/20) is processed without verifying the caller's ACL permissions, allowing any authenticated client to delete specific znodes in the data tree regardless of the ACL restrictions on the znode or its parent. This opcode is considered internal-only and the official client doesn't have API for it, but a client that can open a plain TCP session on the ZooKeeper client port (2181 by default) - with NO authentication and NO ACL permissions - can delete any empty persistent znode (including regular persistent nodes, container nodes, and TTL nodes) by issuing the raw protocol OpCode deleteContainer (20). The deleteContainer request path completely skips both the session check and the DELETE ACL check that are enforced by the regular delete (OpCode 2) path. This is an authorization bypass / ACL enforcement bug. This issue affects Apache ZooKeeper: from 3.9.0 through 3.9.5, from 3.8.0 through 3.8.6. Users are recommended to upgrade to version 3.9.6 or 3.8.7, which fixes the issue.",
"evidence": "osv:UBUNTU-CVE-2026-79993",
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{
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{
"value": "3.4.13-6ubuntu3",
"evidence": "/affected/4/versions"
},
{
"value": "3.4.13-6ubuntu4",
"evidence": "/affected/4/versions"
},
{
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"evidence": "/affected/4/versions"
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]
},
{
"name": {
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"evidence": "/affected/5/package/name"
},
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{
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"evidence": "/affected/5/versions"
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{
"value": "3.9.1-1",
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{
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{
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{
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{
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"evidence": "/affected/7/versions"
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{
"value": "3.9.3-1build3",
"evidence": "/affected/7/versions"
},
{
"value": "3.9.4-1",
"evidence": "/affected/7/versions"
},
{
"value": "3.9.5-1",
"evidence": "/affected/7/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-79993",
"aliases": [
"UBUNTU-CVE-2026-79993"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
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},
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"3.4.8-1",
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},
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},
{
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],
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},
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},
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},
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{
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{
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]
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}
],
"modified": "2026-10-17T13:01:10.231233203Z",
"provider": "osv",
"upstream": [
"CVE-2026-79993"
],
"references": [
"https://ubuntu.com/security/CVE-2026-79993",
"https://www.cve.org/CVERecord?id=CVE-2026-79993"
]
},
"related_cves": [
{
"value": "CVE-2026-79993",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361117,
"published_at": "2026-09-16T10:16:00+00:00"
}