CVE-2026-70452Network attack vector

Unauthorized module access via failed hostname lookup

Published Aug 13, 2026 · Updated Aug 13, 2026

Access control bypass in rsync 3.1.0 through 3.4.4 allows remote attackers to access denied daemon modules after a DNS lookup failure. match_hostname() returns a failed forward lookup as no match, so allow_access() falls through and admits a connection blocked by hosts deny. Exposure requires daemon mode, a hostname token in hosts deny, default-enabled forward lookup, and either a transient resolver failure or a global daemon chroot lacking resolver configuration.

CVSS severity9.1
Critical
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Access control bypass in rsync 3.1.0 through 3.4.4 allows remote attackers to access denied daemon modules after a DNS lookup failure. match_hostname() returns a failed forward lookup as no match, so allow_access() falls through and admits a connection blocked by hosts deny. Exposure requires daemon mode, a hostname token in hosts deny, default-enabled forward lookup, and either a transient resolver failure or a global daemon chroot lacking resolver configuration.

The record

CVE
CVE-2026-70452
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
Rsync Project
Product
rsync
Classifications
CWE-863, CWE-636, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.1.0 <=3.4.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rsync Project · rsyncversion=3.1.0 <=3.4.4

Published CVSS scores

9.1VulnCheckCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
7.4Rsync ProjectCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
CWE-636Not Failing Securely ('Failing Open')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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