# 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.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Aug 2026
- **Updated:** 14 Aug 2026
- **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, UBUNTU-CVE-2026-53794

## 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 (Improper Validation of Specified Quantity in Input)

## Which versions are affected by CVE-2026-53794?


## How do I fix CVE-2026-53794?

Upgrade to a fixed version.

## Is CVE-2026-53794 being exploited?

There is no known exploitation of CVE-2026-53794 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53794 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-53794 in the wild and no public exploit code.

Affected product: RsyncProject rsync. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53794/ (Markdown: https://insights.sbomify.com/CVE-2026-53794/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53794
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53794
- OSV: https://osv.dev/vulnerability/CVE-2026-53794

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53794/
Summaries are generated and may contain mistakes; the official description above is the record.