CVE-2026-16615

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-07-22 17:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-01 18:17 UTC Last updatedMost recent change to the record

Details

Published

2026-07-22 17:16 UTC

Last modified

2026-09-01 18:17 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-338

Record status

Awaiting Analysis

Attack profile CVSS 3.1 · 6.8

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None