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

Read the record on cve.org

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

CVSSScoreVectorSource
3.16.8 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:Nredhat

Weaknesses

  • CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Affected Products

ProductVersions
librestGNOME
    Red Hat Enterprise Linux 10Red Hat
    • 0:0.9.1-11.el10_2.1 and laterNot affected
    Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat
    • 0:0.9.1-11.el10_0.1 and laterNot affected

    References

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