CVE-2026-70452 rsync 3.1.0 < 3.5.0 Access Control Bypass via DNS Resolution Failure
Remote attackers can bypass hostname-based access controls in rsync by triggering DNS failures, gaining unauthorized access to restricted file trees.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-70452?
CVE-2026-70452 is a critical authentication bypass vulnerability in RsyncProject rsync, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-70452?
How do I fix CVE-2026-70452?
Upgrade to a fixed version.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-70452 being exploited?
There is no known exploitation of CVE-2026-70452 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-70452, AZL-95795, BELL-CVE-2026-70452, DEBIAN-CVE-2026-70452, ECHO-bdc4-0ff5-9a3d, GHSA-6692-28cx-wpqq and 2 more.