CVE-2026-70452

critical

Description

rsync 3.1.0 before 3.5.0 contains an access control bypass vulnerability that allows remote attackers to circumvent hosts deny rules by inducing DNS resolution failures during hostname-based access control evaluation. When a DNS lookup for a hostname-based deny rule fails, the daemon skips the rule rather than defaulting to a deny decision, enabling attackers who can trigger DNS failures to bypass module-level IP access controls and gain unauthorized access to restricted module file trees.

References

https://www.vulncheck.com/advisories/rsync-access-control-bypass-via-dns-resolution-failure

https://github.com/RsyncProject/rsync/security/advisories/GHSA-6692-28cx-wpqq

https://github.com/RsyncProject/rsync/releases/tag/v3.5.0

Details

Source: Mitre, NVD

Published: 2026-08-13

Updated: 2026-08-13

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.4

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Severity: High

CVSS v4

Base Score: 9.1

Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Severity: Critical