Vulnerability Details CVE-2026-10097
wolfSSL's AVX2-optimized ML-KEM implementation (mlkem_cmp_avx2) compares only 1536 of the 1568 ciphertext bytes during the Fujisaki-Okamoto re-encryption check in ML-KEM-1024 decapsulation. Ciphertexts that differ from the expected re-encryption solely in bytes 1536-1567 bypass implicit rejection and are accepted as valid, breaking IND-CCA2 security. An attacker able to submit chosen ciphertexts to a decapsulation oracle that uses a static ML-KEM-1024 key, and to observe whether the genuine shared secret or the implicit-rejection secret was produced, can use this as a plaintext-checking oracle to recover the private key. A proof of concept recovered a full ML-KEM-1024 private key with approximately 98% success using roughly 350 chosen ciphertexts. The flaw is a deterministic logic error and does not rely on timing measurements.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 5.6%
CVSS Severity
CVSS v3 Score 7.5
Products affected by CVE-2026-10097
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cpe:2.3:a:wolfssl:wolfssl:5.7.0
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cpe:2.3:a:wolfssl:wolfssl:5.7.2
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cpe:2.3:a:wolfssl:wolfssl:5.7.4
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cpe:2.3:a:wolfssl:wolfssl:5.7.6
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cpe:2.3:a:wolfssl:wolfssl:5.8.0
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cpe:2.3:a:wolfssl:wolfssl:5.8.2
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cpe:2.3:a:wolfssl:wolfssl:5.8.4