CVE-2026-23989 is a high-severity (CVSS 8.2) CWE-863 vulnerability in github.com/opencloud-eu/reva/v2. O3 Security confirms whether CVE-2026-23989 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
REVA Public Link Exploit
Real-World Exposure
github.com/opencloud-eu/reva/v2🐹github.com/opencloud-eu/reva/v2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
REVA is an interoperability platform. Prior to 2.42.3 and 2.40.3, a bug in the GRPC authorization middleware of the "Reva" component of OpenCloud allows a malicious user to bypass the scope verification of a public link. By exploiting this via the the "archiver" service this can be leveraged to create an archive (zip or tar-file) containing all resources that this creator of the public link has access to. This vulnerability is fixed in 2.42.3 and 2.40.3.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/opencloud-eu/reva/v2 | all versions | 2.40.3 |
| 🐹Go | github.com/opencloud-eu/reva/v2 | ≥ 2.41.0&&< 2.42.3 | 2.42.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/opencloud-eu/reva/v2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/opencloud-eu/reva/v2 to 2.40.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23989 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-23989 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-23989. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-23989 in your dependencies?
O3 detects CVE-2026-23989 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.