CVE-2026-53794 rsync < 3.5.0 Denial of Service via --max-alloc=0 Logic Error
Attackers can cause denial of service in rsync receivers by exploiting a logic error in --max-alloc handling that disables memory allocation limits.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53794?
CVE-2026-53794 is a medium-severity denial of service 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 before 3.5.0 contains a logic error in --max-alloc handling that allows a sender or configuration setting --max-alloc=0 to disable allocation sanity checks entirely rather than enforcing a zero-byte cap. Attackers can exploit this flaw to cause the receiver to attempt unbounded memory allocations for file list and data structures, potentially exhausting available memory and causing a denial of service.
Weakness: CWE-1284
Which versions are affected by CVE-2026-53794?
How do I fix CVE-2026-53794?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-53794 being exploited?
There is no known exploitation of CVE-2026-53794 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-53794, AZL-95837, BELL-CVE-2026-53794, DEBIAN-CVE-2026-53794, ECHO-7505-d295-8ceb, GHSA-p827-vwcp-m964 and 1 more.