A heap use‑after‑free bug exists in the error-cleanup path of wolfSSL’s TLS 1.3 post‑quantum cryptography hybrid key share processing. When an error occurs, an internal function frees a Kyber key object, and a later call attempts to zero‑out that already‑freed object, writing zeroes to freed heap memory. This produces an undefined memory write that can crash the application and corrupt program state. The weakness is mapped to CWE‑416.

The vulnerability affects the wolfSSL cryptographic library, specifically the TLS 1.3 implementation that supports PQC hybrid key share. Because no specific version ranges are listed, any wolfSSL release that includes PQC hybrid key share before the fix is potentially impacted.

The CVSS base score of 6.3 indicates moderate severity. EPSS data is not available and the vulnerability is not listed in the CISA KEV catalogue. A likely attack vector, inferred from the functionality described, would involve an adversary initiating a TLS 1.3 handshake using a PQC hybrid key share to trigger the error path and overwrite freed memory. The CVE description does not confirm that arbitrary code execution can result; the primary expected impact is denial of service through application crash or corruption of program state.