# CVE-2026-79781: rclone serve s3 Path Traversal via dot-dot object keys

> Attackers can read and overwrite root-level files by using dot-dot segments in S3 object keys when using rclone serve s3.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/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:** 25 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** BIT-rclone-2026-79781, DEBIAN-CVE-2026-79781, GHSA-8v25-v8p6-qf7v, GHSA-98fh-ch8q-6529, GO-2026-6189, MINI-262f-j9xw-96jm, MINI-2q2g-433r-h3fq, MINI-7585-jrh3-p75v, MINI-8434-p585-g2q7, MINI-8f9x-c326-r5q9, MINI-x3g9-7vj7-9g6w, UBUNTU-CVE-2026-79781

## What is CVE-2026-79781?

CVE-2026-79781 is a medium-severity path traversal vulnerability in rclone, published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

rclone serve s3 before 1.74.4 contains a path traversal vulnerability that allows attackers to read and overwrite root-level files by using dot-dot segments in S3 object keys. Attackers can send requests with object keys like ../root-secret.txt to escape the bucket namespace and access files in the serve root directory.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-79781?

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 | All versions | 1.74.4 |
| `github.com/rclone/rclone` | Go | All versions | 1.74.4 |
| `github.com/rclone/rclone` | Go | All versions | 1.74.4 |
| `rclone` | Bitnami | All versions | 1.74.4 |

## How do I fix CVE-2026-79781?

Upgrade github.com/rclone/rclone to 1.74.4 or later.

## Is CVE-2026-79781 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-79781 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-79781 and fix it if it is affected.

What it is: CVE-2026-79781 is a medium-severity path traversal vulnerability in rclone, published on 25 Aug 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-2026-79781 exists.

Affected packages and fixed versions:
- github.com/rclone/rclone (Go): affected all versions; fixed in 1.74.4
- github.com/rclone/rclone (Go): affected all versions; fixed in 1.74.4
- github.com/rclone/rclone (Go): affected all versions; fixed in 1.74.4
- rclone (Bitnami): affected all versions; fixed in 1.74.4

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-2026-79781/ (Markdown: https://insights.sbomify.com/CVE-2026-79781/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-79781
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-79781
- OSV: https://osv.dev/vulnerability/CVE-2026-79781

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-79781/
Summaries are generated and may contain mistakes; the official description above is the record.