# CVE-2026-116188: rclone serve s3 1.75.0 before 1.75.2 Memory Limit Bypass via Multipart Overflow


- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 25 Oct 2026
- **Updated:** 25 Oct 2026
- **Also known as:** BIT-rclone-2026-116188, DEBIAN-CVE-2026-116188, GHSA-6475-788v-w6c3, GHSA-qjw8-8hmp-c3m6, UBUNTU-CVE-2026-116188

## What is CVE-2026-116188?

CVE-2026-116188 is a medium-severity vulnerability in rclone, published on 25 Oct 2026. 

### Official description

rclone serve s3 versions 1.75.0 before 1.75.2 contain an integer overflow vulnerability in multipart reorder-memory accounting that bypasses the configured buffer limit. Attackers can open two concurrent current-part PUT requests declaring huge lengths to wrap the signed int64 counter and retain out-of-order parts in memory, exhausting the host.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-116188?

1 open source package ship an affected version, including rclone. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `rclone` | Bitnami | From 1.75.0 | 1.75.2 |

Products: Rclone Rclone.

## How do I fix CVE-2026-116188?

Upgrade rclone to 1.75.2 or later.

## Is CVE-2026-116188 being exploited?

There is no known exploitation of CVE-2026-116188 in the wild and no public exploit code.

## Other vulnerabilities in rclone

- [CVE-2026-88018](https://insights.sbomify.com/CVE-2026-88018/): rclone serve s3: --auth-proxy without --auth-key authenticates nobody - full SigV4 signature bypass (critical 9.8)
- [CVE-2026-49980](https://insights.sbomify.com/CVE-2026-49980/): Rclone: Unauthenticated command execution in `rclone rcd --rc-serve` via inline remote instantiation, bypassing CVE-2026-41179 fix (critical 9.8)
- [CVE-2026-41179](https://insights.sbomify.com/CVE-2026-41179/): RClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command execution (critical 9.2)
- [CVE-2026-41176](https://insights.sbomify.com/CVE-2026-41176/): Rclone: Unauthenticated options/set allows runtime auth bypass, leading to sensitive operations and command execution (critical 9.2)
- [CVE-2026-59733](https://insights.sbomify.com/CVE-2026-59733/): rclone `serve restic --private-repos` authorization bypass: `..` in the URL path lets an authenticated user read, overwrite and delete other users' repositories (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-116188 and fix it if it is affected.

What it is: CVE-2026-116188 is a medium-severity vulnerability in rclone, published on 25 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-116188 in the wild and no public exploit code.

Affected packages and fixed versions:
- rclone (Bitnami): affected from 1.75.0; fixed in 1.75.2

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-2026-116188/ (Markdown: https://insights.sbomify.com/CVE-2026-116188/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-116188
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116188
- OSV: https://osv.dev/vulnerability/CVE-2026-116188

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-116188/
Summaries are generated and may contain mistakes; the official description above is the record.