A flaw was discovered in the GnuTLS Datagram Transport Layer Security (DTLS) implementation. The comparator that orders packets by sequence number fails to handle duplicate sequence numbers, which can cause unstable ordering or undefined behavior. When an attacker sends crafted DTLS packets with repeated sequence numbers, the affected service may crash or become otherwise unusable, resulting in a denial of service. The weakness is identified as CWE-475, indicating an improper comparison of data values.

The vulnerability affects Red Hat Enterprise Linux 10, 9, 8, 7, and 6, including Red Hat Hardened Images, as well as Red Hat OpenShift Container Platform 4. All of these include the GnuTLS library containing the faulty comparator logic.

The CVSS score of 7.5 reflects a high severity impact for remote attackers. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog, suggesting that it is not currently known to be exploited in the wild. The likely attack vector is remote over a network where the vulnerable system receives DTLS traffic. No authentication or privileged access is required; any host that sends malicious DTLS packets can trigger the denial of service. Because the flaw manifests as a crash or hang, the primary impact is a single‑point disruption of services that rely on DTLS, which can cascade in a clustered or high‑availability environment.