# CVE-2026-88044: rclone: RC per-server auth-proxy bypass

> Attackers can bypass authentication in rclone's FTP and S3 servers by exploiting a configuration check error, gaining unauthorized access to data.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** BIT-rclone-2026-88044, DEBIAN-CVE-2026-88044, GHSA-p569-5gjg-9cmj, GO-2026-6460, MINI-79jr-2666-9362, MINI-9ww7-6g85-mfpg, MINI-j2h4-79m9-pchx, MINI-x55f-5mrh-334r, ROOT-APP-GOBINARY-CVE-2026-88044, UBUNTU-CVE-2026-88044

## What is CVE-2026-88044?

CVE-2026-88044 is a critical authentication bypass vulnerability in rclone, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.70.0 until 1.75.1, the serve/start RC interface accepts per-server proxyOpt.AuthProxy settings, and the FTP and S3 constructors in cmd/serve/ftp/ftp.go and cmd/serve/s3/server.go incorrectly check the process-global proxy.Opt.AuthProxy value instead. When the global value is empty, the request-local authentication proxy is ignored: FTP falls back to the fixed filesystem with username anonymous and any password, while S3 with AuthKey serves the fixed RC fs rather than the backend selected by the proxy. The dedicated command-line servers that configure the global option are not affected. This issue is fixed in version 1.75.1.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-88044?

4 open source packages ship an affected version, including github.com/rclone/rclone and rclone.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/rclone/rclone` | Go | From 1.70.0 | 1.75.1 |
| `github.com/rclone/rclone` | Go | From 1.70.0 | 1.75.1 |
| `github.com/rclone/rclone` | Go | From 1.70.0 | 1.75.1 |
| `rclone` | Bitnami | From 1.70.0 | 1.75.1 |

## How do I fix CVE-2026-88044?

Upgrade github.com/rclone/rclone to 1.75.1 or later.

## Is CVE-2026-88044 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88044 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88044 and fix it if it is affected.

What it is: CVE-2026-88044 is a critical authentication bypass vulnerability in rclone, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88044 exists.

Affected packages and fixed versions:
- github.com/rclone/rclone (Go): affected from 1.70.0; fixed in 1.75.1
- github.com/rclone/rclone (Go): affected from 1.70.0; fixed in 1.75.1
- github.com/rclone/rclone (Go): affected from 1.70.0; fixed in 1.75.1
- rclone (Bitnami): affected from 1.70.0; fixed in 1.75.1

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-2026-88044/ (Markdown: https://insights.sbomify.com/CVE-2026-88044/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88044
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88044
- OSV: https://osv.dev/vulnerability/CVE-2026-88044

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88044/
Summaries are generated and may contain mistakes; the official description above is the record.