# CVE-2026-53783: rsync < 3.5.0 TOCTOU Race Condition Directory Escape via rrsync

> Authenticated attackers can exploit a race condition in rrsync to bypass directory restrictions and read or write files outside the permitted subtree.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **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-2026-53783, AZL-95825, BELL-CVE-2026-53783, CLSA-2026-1791480690, CLSA-2026-1792576195, CLSA-2026-1792659934, DEBIAN-CVE-2026-53783, ECHO-2923-d825-c1f1, GHSA-9cgc-64g4-3gv5, ROOT-OS-DEBIAN-11-CVE-2026-53783, UBUNTU-CVE-2026-53783

## What is CVE-2026-53783?

CVE-2026-53783 is a high-severity vulnerability in RsyncProject rsync, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as --copy-unsafe-links, -D, and --log-file through rrsync to read or write files outside the permitted directory subtree.

Weakness: CWE-88 (Improper Neutralization of Argument Delimiters in a Command), CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-53783?


## How do I fix CVE-2026-53783?

Upgrade to a fixed version.

## Is CVE-2026-53783 being exploited?

There is no known exploitation of CVE-2026-53783 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53783 and fix it if it is affected.

What it is: CVE-2026-53783 is a high-severity vulnerability in RsyncProject rsync, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53783 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-2026-53783/ (Markdown: https://insights.sbomify.com/CVE-2026-53783/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53783
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53783
- OSV: https://osv.dev/vulnerability/CVE-2026-53783

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53783/
Summaries are generated and may contain mistakes; the official description above is the record.