# CVE-2026-45232: Rsync < 3.4.3 Off-by-One Stack Write via HTTP Proxy

> Network attackers can corrupt stack memory and potentially execute code by sending malformed HTTP proxy responses to Rsync clients configured with a proxy.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 20 May 2026
- **Updated:** 14 Jul 2026
- **Also known as:** ALPINE-CVE-2026-45232, AZL-86997, BELL-CVE-2026-45232, CLSA-2026-1780922909, CLSA-2026-1782981361, DEBIAN-CVE-2026-45232, ECHO-349a-47bf-367b, GHSA-8f85-j2cv-59m8, JLSEC-2026-632, UBUNTU-CVE-2026-45232

## What is CVE-2026-45232?

CVE-2026-45232 is a low-severity memory corruption vulnerability in RsyncProject rsync, published on 20 May 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 versions before 3.4.3 contain an off-by-one out-of-bounds stack write vulnerability in the establish_proxy_connection() function in socket.c that allows network attackers to corrupt stack memory by sending a malformed HTTP proxy response. Attackers can exploit this by positioning themselves between the client and proxy or controlling the proxy server to send a response line of 1023 or more bytes without a newline terminator, causing a null byte to be written to an out-of-bounds stack address when the RSYNC_PROXY environment variable is set.

Weakness: CWE-193 (Off-by-one Error)

## Which versions are affected by CVE-2026-45232?

It affects 1 product.


Products: Samba Rsync.

## How do I fix CVE-2026-45232?

Upgrade to a fixed version.

## Is CVE-2026-45232 being exploited?

There is no known exploitation of CVE-2026-45232 in the wild and no public exploit code.

## Other vulnerabilities in RsyncProject rsync

- [CVE-2017-15994](https://insights.sbomify.com/CVE-2017-15994/): Security feature bypass in n/a (critical 9.8)
- [CVE-2026-53791](https://insights.sbomify.com/CVE-2026-53791/): rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header (critical 9.1)
- [CVE-2026-70461](https://insights.sbomify.com/CVE-2026-70461/): rsync 3.2.5 < 3.5.0 Heap Out-of-Bounds Write via files-from Entry (high 8.8)
- [CVE-2026-70455](https://insights.sbomify.com/CVE-2026-70455/): rsync 3.4.2 < 3.5.0 DoS via --zt Zstandard Compression Thread Exhaustion (high 8.7)
- [CVE-2026-70463](https://insights.sbomify.com/CVE-2026-70463/): rsync 3.1.0 < 3.5.0 Authorization Bypass via auth users Directive Parsing (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45232 and fix it if it is affected.

What it is: CVE-2026-45232 is a low-severity memory corruption vulnerability in RsyncProject rsync, published on 20 May 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-2026-45232 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-2026-45232/ (Markdown: https://insights.sbomify.com/CVE-2026-45232/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45232
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45232
- OSV: https://osv.dev/vulnerability/CVE-2026-45232

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45232/
Summaries are generated and may contain mistakes; the official description above is the record.