{"id":"CVE-2026-10097","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-10097","generatedAt":"2026-10-28T07:04:01.930Z","title":"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.","description":"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.","published":"2026-06-25T20:17:09.000Z","lastModified":"2026-06-26T17:16:32.000Z","status":"Modified","sourceIdentifier":"facts@wolfssl.com","cvss":{"version":"4.0","score":8.3,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-697"],"affected":["wolfssl/wolfssl"],"epss":{"score":0.00262,"percentile":0.1789,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/wolfSSL/wolfssl/pull/10430","tags":["Issue Tracking","Patch"],"source":"facts@wolfssl.com"},{"url":"https://www.wolfssl.com/docs/security-vulnerabilities/","tags":["Vendor Advisory"],"source":"facts@wolfssl.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-10097","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}