CVE-2026-16615
Librest: weak random number generation in pkce implementation
- State
- Published
- Severity
- 6.8 Medium
- Published
- Jul 22, 2026
- Updated
- Sep 1, 2026
- Reserved
- Jul 22, 2026
Description
A flaw was found in librest. The PKCE implementation for OAuth authorization uses the GRand function from the GLib API, a cryptographically insecure pseudo-random number generator. Because the generated "code verifier" lacks sufficient cryptographic entropy, a malicious actor can reverse-engineer the pseudo-random number generator (PRNG) seed to predict or reconstruct the code verifier string, allowing an attacker to bypass PKCE protections and successfully impersonate the client during the OAuth 2.0 authorization flow.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.8 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N | redhat |
Weaknesses
- CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Affected Products
| Product | Versions |
|---|---|
librestGNOME | |
Red Hat Enterprise Linux 10Red Hat |
|
Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat |
|
References
- RHSA-2026:47085vendor-advisory
- RHSA-2026:62222vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-16615vdb-entry
- RHBZ#2504432issue-tracking
- https://gitlab.gnome.org/GNOME/librest/-/issues/25
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