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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
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 | 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 |
1 more packages
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.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-55495 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55495 exists.
Sources
Also known as GHSA-49h3-cwhj-4737, GO-2026-6097.