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Public Link Exploit

High
dragotin published GHSA-vf5j-r2hw-2hrw Feb 5, 2026

Package

opencloud (OpenCloud)

Affected versions

stable releases 4.0.x
rolling releases <= 5.0.1

Patched versions

>= 4.0.3
>= 5.0.2

Description

Impact

A security issue was discovered in Reva that enables a malicious user to bypass the scope validation of a public link. That allows it to access resources outside the scope of a public link.

OpenCloud uses Reva as one of it's core components and thus it is affected.

Patches

Update to OpenCloud version >= 4.0.3 (stable release)
Update to OpenCloud version >= 5.0.2 (rolling release)

Workarounds

If you are unable to update immediately, please implement the following security configuration to disable public link shares temporarily until the final solution for this problem is rolled out.

Configuration Adjustment

  • Docker Compose: Edit the docker-compose.yml and add GATEWAY_STORAGE_PUBLIC_LINK_ENDPOINT=“” (empty string value) in the environment section of the opencloud container.

Verification of Mitigation

Execute the following test:

  • Create a public link for testing.
  • Open the link url in a private (no active login) browser tab.
  • You should see an error page “unknown error”.

This configuration provides immediate protection and should be implemented immediately.
Configuration mitigation is available. It mitigates the problem completely.

References

No references yet

For more information

If you have any questions or comments about this advisory:

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

CVE ID

CVE-2026-23989

Weaknesses

No CWEs

Credits