High
rsync 2.0.0 < 3.5.0 Connection Slot Exhaustion DoS via Handshake Stall
Type: advisorySources: OSV
rsync daemon 2.0.0 before 3.5.0 contains a denial of service vulnerability that allows unauthenticated remote attackers to exhaust daemon connection slots by stalling the handshake process before or after module selection without triggering the I/O timeout. Attackers can open many simultaneous connections and trickle data at the minimum rate to avoid timeout, or stall entirely before module selection where no timeout applies, consuming all available connection slots and denying service to legitimate clients.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-70464
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 5 Nov 2026, 01:52 UTC · Revision 1
Source evidence
rsync 2.0.0 < 3.5.0 Connection Slot Exhaustion DoS via Handshake Stall
core-osv · Original sourcePublished 13 Aug 2026, 14:41 UTC
rsync daemon 2.0.0 before 3.5.0 contains a denial of service vulnerability that allows unauthenticated remote attackers to exhaust daemon connection slots by stalling the handshake process before or after module selection without triggering the I/O timeout. Attackers can open many simultaneous connections and trickle data at the minimum rate to avoid timeout, or stall entirely before module selection where no timeout applies, consuming all available connection slots and denying service to legitimate clients.
osv:CVE-2026-70464
Complete source record
{
"id": "7099f94a578e52b788a469d80e484292f1afb0ae63eb6e829458e9b7cceef8a2",
"url": "https://osv.dev/vulnerability/CVE-2026-70464",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "rsync 2.0.0 < 3.5.0 Connection Slot Exhaustion DoS via Handshake Stall",
"summary": "rsync daemon 2.0.0 before 3.5.0 contains a denial of service vulnerability that allows unauthenticated remote attackers to exhaust daemon connection slots by stalling the handshake process before or after module selection without triggering the I/O timeout. Attackers can open many simultaneous connections and trickle data at the minimum rate to avoid timeout, or stall entirely before module selection where no timeout applies, consuming all available connection slots and denying service to legitimate clients.",
"evidence": "osv:CVE-2026-70464",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-70464",
"aliases": [
"CVE-2026-70464",
"GHSA-hrwq-ccf7-rw5m"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/rsyncproject/rsync",
"type": "GIT",
"events": [
{
"introduced": "c725d76c5a54acddbf62d7c4cf04a16dd7d17f31"
},
{
"fixed": "471e17dc0d68233db84db11be82c9f62f4661214"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "2.0.0"
},
{
"last_affected": "3.4.4"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"range": [
{
"fixed": "471e17dc0d68233db84db11be82c9f62f4661214"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v3.5.0"
}
]
}
}
],
"versions": [
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"v3.4",
"v3.2.7",
"v3.4.1",
"v3.4.2",
"v3.4.0",
"v3.3.0",
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"v3.2.1pre1",
"v3.2.0",
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"v3.2.0pre2",
"v3.2.0pre1",
"v3.1.3",
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"v2.6.9",
"v2.6.9pre3",
"v2.6.9pre2",
"v2.6.9pre1",
"v2.6.8",
"v2.6.8pre1",
"v2.6.7",
"v2.6.7pre3",
"v2.6.7pre2",
"v2.6.7pre1",
"v2.6.6pre1",
"v2.6.5",
"v2.6.5pre2",
"v2.6.5pre1",
"v2.6.4",
"v2.6.4pre4",
"v2.6.4pre3",
"v2.6.4pre2",
"v2.6.4pre1",
"v2.6.3",
"v2.6.3pre2",
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"v2.6.2",
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"v2.5.3",
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"v2.5.2",
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"v2.5.2pre1",
"v2.5.1",
"v2.5.1pre3",
"v2.5.1pre2",
"v2.5.1pre1",
"v2.5.0",
"v2.4.7pre4",
"v2.4.7pre2",
"mbp_bk_export0",
"v2.4.6",
"v2.4.5",
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"v2.4.3",
"v2.4.2",
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"v2.4.0",
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"v2.3.1",
"v2.3.0",
"v2.2.1",
"v2.2.0",
"v2.1.1",
"v2.1.0",
"v2.0.19",
"v2.0.18",
"v2.0.17",
"v2.0.16",
"v2.0.15",
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"v2.0.13",
"v2.0.12",
"v2.0.11",
"v2.0.10",
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-70464.json"
}
}
],
"modified": "2026-10-28T02:30:41.553652429Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/70xxx/CVE-2026-70464.json",
"https://github.com/RsyncProject/rsync/releases/tag/v3.5.0",
"https://github.com/RsyncProject/rsync/security/advisories/GHSA-hrwq-ccf7-rw5m",
"https://nvd.nist.gov/vuln/detail/CVE-2026-70464",
"https://www.vulncheck.com/advisories/rsync-connection-slot-exhaustion-dos-via-handshake-stall",
"https://github.com/RsyncProject/rsync"
],
"provider_metadata": {
"cwe_ids": [
"CWE-770"
],
"cna_assigner": "VulnCheck",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/70xxx/CVE-2026-70464.json"
}
},
"related_cves": [
{
"value": "CVE-2026-70464",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 509233,
"published_at": "2026-08-13T14:41:47.987+00:00"
}