The vulnerability allows an attacker to remove or inject bytes at the beginning of a TLS 1.3 stream by causing an entropy source to fail in certain Mbed TLS releases. This flaw can alter the integrity of the TLS handshake, potentially leading to spoofed or corrupted connections. Its CVSS score of 2.9 indicates a low overall severity, but the impact is limited to the data integrity of the TLS session rather than full system compromise.

Affected versions of Mbed TLS include 3.2.0 through 3.6.6 and 4.0.0 through 4.1.0. Only TLS 1.3 server configurations are impacted, and the vendors or product families impacted are those that ship the Trusted Firmware implementation of Mbed TLS. The flaw does not affect earlier or later releases.

The CVSS score indicates low severity and the EPSS score is not available. The flaw is not recorded in the CISA KEV catalog. Exploitation requires control over or the ability to manipulate an entropy source used by the server, which suggests a higher technical barrier and a lower likelihood of widespread attacks. Nevertheless, because the flaw can modify the service stream, operators of vulnerable servers should treat it as a significant integrity issue.