Critical
rsync — security advisory
rsync daemon before 3.5.0 contains an IP address spoofing vulnerability that allows unauthenticated remote attackers to bypass IP-based access controls by sending a crafted PROXY protocol header with a forged source address. Attackers who can connect directly to the rsync daemon can inject a spoofed source IP in the PROXY protocol header to circumvent hosts allow/deny rules, gaining unauthorized access that would otherwise be blocked based on their real source address.
- Products
- rsync
- Affected versions
- 3.0.9-4ubuntu1, 3.1.0-2, 3.1.0-2ubuntu0.1, 3.1.0-2ubuntu0.2, 3.1.0-2ubuntu0.3, 3.1.0-2ubuntu0.4, 3.1.0-2ubuntu0.4+esm1, 3.1.0-2ubuntu0.4+esm2, 3.1.0-2ubuntu0.4+esm3, 3.1.0-2ubuntu0.4+esm4, 3.1.1-3, 3.1.1-3ubuntu1, 3.1.1-3ubuntu1.1, 3.1.1-3ubuntu1.2, 3.1.1-3ubuntu1.3, 3.1.1-3ubuntu1.3+esm1, 3.1.1-3ubuntu1.3+esm2, 3.1.1-3ubuntu1.3+esm3, 3.1.1-3ubuntu1.3+esm4, 3.1.1-3ubuntu1.3+esm5, 3.1.1-3ubuntu1.3+esm6, 3.1.2-2, 3.1.2-2.1, 3.1.2-2.1ubuntu1, 3.1.2-2.1ubuntu1.1, 3.1.2-2.1ubuntu1.2, 3.1.2-2.1ubuntu1.3, 3.1.2-2.1ubuntu1.4, 3.1.2-2.1ubuntu1.5, 3.1.2-2.1ubuntu1.6, 3.1.2-2.1ubuntu1.6+esm1, 3.1.2-2.1ubuntu1.6+esm2, 3.1.2-2.1ubuntu1.6+esm3, 3.1.2-2.1ubuntu1.6+esm4, 3.1.3-6, 3.1.3-8, 3.1.3-8ubuntu0.1, 3.1.3-8ubuntu0.2, 3.1.3-8ubuntu0.3, 3.1.3-8ubuntu0.4, 3.1.3-8ubuntu0.5, 3.1.3-8ubuntu0.7, 3.1.3-8ubuntu0.8, 3.1.3-8ubuntu0.9, 3.1.3-8ubuntu0.9+esm1, 3.1.3-8ubuntu0.9+esm2, 3.2.3-4ubuntu1, 3.2.3-4ubuntu2, 3.2.3-8ubuntu1, 3.2.3-8ubuntu2, 3.2.3-8ubuntu3, 3.2.3-8ubuntu3.1, 3.2.7-0ubuntu0.22.04.2, 3.2.7-0ubuntu0.22.04.3, 3.2.7-0ubuntu0.22.04.4, 3.2.7-0ubuntu0.22.04.6, 3.2.7-0ubuntu0.22.04.7, 3.2.7-1, 3.2.7-1build1, 3.2.7-1build2, 3.2.7-1ubuntu1, 3.2.7-1ubuntu1.1, 3.2.7-1ubuntu1.2, 3.2.7-1ubuntu1.4, 3.2.7-1ubuntu1.5, 3.4.1+ds1-5ubuntu1, 3.4.1+ds1-6, 3.4.1+ds1-7, 3.4.1+ds1-7ubuntu0.2, 3.4.1+ds1-7ubuntu0.3, 3.4.4+ds1-1, 3.4.4+ds1-1build1, 3.5.0+ds1-2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-53791
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:29 UTC · Revision 1
Source evidence
rsync daemon before 3.5.0 contains an IP address spoofing vulnerability that allows unauthenticated remote attackers to bypass IP-based access controls by sending a crafted PROXY protocol header with a forged source address. Attackers who can connect directly to the rsync daemon can inject a spoofed source IP in the PROXY protocol header to circumvent hosts allow/deny rules, gaining unauthorized access that would otherwise be blocked based on their real source address.
osv:UBUNTU-CVE-2026-53791
rsync
Fixed versions: Not specified
rsync
Fixed versions: Not specified
rsync
Fixed versions: Not specified
rsync
Fixed versions: Not specified
rsync
Fixed versions: Not specified
rsync
Fixed versions: Not specified
rsync
Fixed versions: Not specified
rsync
Fixed versions: Not specified
Complete source record
{
"id": "44073a93e0a0dc6ccfc3acdd3c95a9b756343664e05d94abc0f3a94b9965ff54",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-53791",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-53791",
"summary": "rsync daemon before 3.5.0 contains an IP address spoofing vulnerability that allows unauthenticated remote attackers to bypass IP-based access controls by sending a crafted PROXY protocol header with a forged source address. Attackers who can connect directly to the rsync daemon can inject a spoofed source IP in the PROXY protocol header to circumvent hosts allow/deny rules, gaining unauthorized access that would otherwise be blocked based on their real source address.",
"evidence": "osv:UBUNTU-CVE-2026-53791",
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{
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{
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{
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{
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{
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{
"value": "3.1.2-2.1ubuntu1.4",
"evidence": "/affected/2/versions"
},
{
"value": "3.1.2-2.1ubuntu1.5",
"evidence": "/affected/2/versions"
},
{
"value": "3.1.2-2.1ubuntu1.6",
"evidence": "/affected/2/versions"
},
{
"value": "3.1.2-2.1ubuntu1.6+esm1",
"evidence": "/affected/2/versions"
},
{
"value": "3.1.2-2.1ubuntu1.6+esm2",
"evidence": "/affected/2/versions"
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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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"evidence": "/affected/3/versions"
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{
"value": "3.1.3-8ubuntu0.9+esm1",
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{
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{
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{
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"aliases": [
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"metrics": [
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},
{
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{
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],
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},
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},
{
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"ecosystem": "Ubuntu:26.10"
},
"versions": [
"3.4.1+ds1-7",
"3.4.4+ds1-1",
"3.4.4+ds1-1build1",
"3.5.0+ds1-2"
],
"database_specific": {
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},
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},
{
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{
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],
"package": {
"name": "rsync",
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},
"versions": [
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"3.4.1+ds1-6",
"3.4.1+ds1-7",
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],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-53791.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "rsync",
"binary_version": "3.4.1+ds1-7ubuntu0.3"
}
]
}
}
],
"modified": "2026-10-17T12:58:36.051011619Z",
"provider": "osv",
"upstream": [
"CVE-2026-53791"
],
"references": [
"https://ubuntu.com/security/CVE-2026-53791",
"https://www.cve.org/CVERecord?id=CVE-2026-53791",
"https://download.samba.org/pub/rsync/NEWS#3.5.0"
]
},
"related_cves": [
{
"value": "CVE-2026-53791",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 358840,
"published_at": "2026-08-13T15:19:00+00:00"
}