# CVE-2026-53792: rsync < 3.5.0 Out-of-Bounds Read via Zero-Length Checksum Block

> A malicious receiver can trigger an out-of-bounds read on the rsync sender by sending a zero-length checksum block, potentially leaking memory or causing a crash.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 13 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** ALPINE-CVE-2026-53792, AZL-95786, BELL-CVE-2026-53792, DEBIAN-CVE-2026-53792, ECHO-bf04-0160-41b5, GHSA-cg57-rp9g-56hw, UBUNTU-CVE-2026-53792

## What is CVE-2026-53792?

CVE-2026-53792 is a high-severity memory corruption vulnerability in RsyncProject rsync, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

rsync before 3.5.0 contains an out-of-bounds read vulnerability in the sender-side block matching logic that allows a malicious receiver to trigger memory access before the start of an allocated buffer by sending a crafted checksum block with a length of zero. Attackers can send a specially crafted checksum set containing a zero-length block to cause a negative offset calculation during delta computation, resulting in an out-of-bounds read of file data buffer memory on the sender side.

Weakness: CWE-787 (Out-of-bounds Write), CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2026-53792?


## How do I fix CVE-2026-53792?

Upgrade to a fixed version.

## Is CVE-2026-53792 being exploited?

There is no known exploitation of CVE-2026-53792 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53792 and fix it if it is affected.

What it is: CVE-2026-53792 is a high-severity memory corruption vulnerability in RsyncProject rsync, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-53792 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-2026-53792/ (Markdown: https://insights.sbomify.com/CVE-2026-53792/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53792
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53792
- OSV: https://osv.dev/vulnerability/CVE-2026-53792

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-53792/
Summaries are generated and may contain mistakes; the official description above is the record.