# CVE-2026-55495: Cloudreve: Path Traversal in WOPI PUT_RELATIVE Allows Arbitrary File Creation in Owner Account

> Attackers can create or overwrite arbitrary files within the owner's account via path traversal in the WOPI PUT_RELATIVE handler.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A: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:** 31 Jul 2026
- **Updated:** 31 Jul 2026
- **Also known as:** GHSA-49h3-cwhj-4737, GO-2026-6097

## What is CVE-2026-55495?

CVE-2026-55495 is a medium-severity path traversal vulnerability in cloudreve, published on 31 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the WOPI PUT_RELATIVE handler passes X-WOPI-SuggestedTarget to URI.JoinRaw as a path rather than a filename, allowing slash and dot-dot segments to escape the source file directory and create or conditionally overwrite files elsewhere in the same owner account. This issue is fixed in version 4.17.0.

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

## Which versions are affected by CVE-2026-55495?

7 open source packages ship an affected version, including github.com/cloudreve/Cloudreve/v3, github.com/cloudreve/Cloudreve and github.com/cloudreve/Cloudreve/v4.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/cloudreve/Cloudreve/v3` | Go | All versions | None |
| `github.com/cloudreve/Cloudreve/v3` | Go | All versions to 3.0.0-20250225100611-da4e44b77af4 | None |
| `github.com/cloudreve/Cloudreve/v3` | Go | All versions to 3.0.0-20250225100611-da4e44b77af4 | None |
| `github.com/cloudreve/Cloudreve` | Go | All versions | None |
| `github.com/cloudreve/Cloudreve/v4` | Go | All versions | 4.0.0-20260613023150-7968e50429ef |
| `github.com/cloudreve/Cloudreve/v4` | Go | All versions | 4.0.0-20260613023150-7968e50429ef |
| `github.com/cloudreve/Cloudreve/v4` | Go | All versions | 4.0.0-20260613023150-7968e50429ef |

## How do I fix CVE-2026-55495?

Upgrade to a fixed version.

## Is CVE-2026-55495 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55495 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55495 and fix it if it is affected.

What it is: CVE-2026-55495 is a medium-severity path traversal vulnerability in cloudreve, published on 31 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55495 exists.

Affected packages and fixed versions:
- github.com/cloudreve/Cloudreve/v3 (Go): affected all versions; no fix listed
- github.com/cloudreve/Cloudreve/v3 (Go): affected all versions up to 3.0.0-20250225100611-da4e44b77af4; no fix listed
- github.com/cloudreve/Cloudreve/v3 (Go): affected all versions up to 3.0.0-20250225100611-da4e44b77af4; no fix listed
- github.com/cloudreve/Cloudreve (Go): affected all versions; no fix listed
- github.com/cloudreve/Cloudreve/v4 (Go): affected all versions; fixed in 4.0.0-20260613023150-7968e50429ef
- github.com/cloudreve/Cloudreve/v4 (Go): affected all versions; fixed in 4.0.0-20260613023150-7968e50429ef
- github.com/cloudreve/Cloudreve/v4 (Go): affected all versions; fixed in 4.0.0-20260613023150-7968e50429ef

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-2026-55495/ (Markdown: https://insights.sbomify.com/CVE-2026-55495/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55495
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55495
- OSV: https://osv.dev/vulnerability/CVE-2026-55495

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55495/
Summaries are generated and may contain mistakes; the official description above is the record.