CVE-2026-16615 GNOME CVE debrief

Who should care

Organizations using librest for OAuth authorization should be aware of this vulnerability and take necessary actions to mitigate the risk. This includes reviewing their current implementation, assessing potential exposure, and applying patches or workarounds provided by the vendor.

Technical summary

The PKCE implementation for OAuth authorization in librest uses the GRand function from the GLib API, which is a cryptographically insecure pseudo-random number generator. This leads to a 'code verifier' with insufficient cryptographic entropy, making it possible for an attacker to reverse-engineer the PRNG seed and predict or reconstruct the code verifier string. This allows an attacker to bypass PKCE protections and impersonate the client during the OAuth 2.0 authorization flow.

Defensive priority

Medium

Recommended defensive actions

• Review and assess the current implementation of librest for OAuth authorization
• Apply patches or workarounds provided by the vendor
• Implement additional security measures to mitigate the risk of impersonation
• Monitor for potential attacks and anomalies in the OAuth authorization flow
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-22T17:16:55.863Z and has not been modified since then. The NVD entry is currently Awaiting Analysis. References include Red Hat security advisories and bugzilla entries.

Official resources