ML-KEM-1024 x64 AVX2 incomplete cipher text comparison enables IND-CCA2 break and static private-key recovery
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-10097
- 2026-10-03 Alias added: GHSA-hcgc-hfp6-58v4
References
More Wolfssl vulnerabilities
- TI-2024-00830 SEGV and out of bounds memory read from malicious packet CVSS 3.1CRITICAL 9.1
- TI-2022-18557 In wolfSSL before 5.5.1, malicious clients can cause a buffer overflow during a TLS 1.3… CVSS 3.1HIGH 7.5
- TI-2025-10943 Potential DoS Vulnerability through Multiple KeyShareEntry with Same Group in TLS 1.3 ClientHello CVSS 4.0MEDIUM 6.3
- TI-2017-09737 wolfSSL Bleichenbacher/ROBOT CVSS 3.0HIGH 7.5
- TI-2019-08902 wolfSSL 4.0.0 has a Buffer Overflow in DoPreSharedKeys in tls13.c when a current identity… CVSS 3.1CRITICAL 9.8
- TI-2017-02021 Improper certificate validation in wolfSSL CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-10097 · CVE Program
- CVE-2026-10097 · NVD
- FIRST EPSS
- GHSA-hcgc-hfp6-58v4 · GitHub Advisory Database · CC BY 4.0
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