CVE-2026-16615

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Enterprise Linux 100:0.9.1-11.el10_2.1 < *unaffected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support0:0.9.1-11.el10_0.1 < *unaffected

Weaknesses

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

Workarounds

Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References