# CVE-2024-36405

## Summary

- **CVE ID:** CVE-2024-36405
- **Severity:** MEDIUM
- **CVSS Score:** 5.9 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)
- **CWE:** CWE-208, CWE-385
- **Published:** Jun 10, 2024
- **Last Modified:** Mar 13, 2026

## Description

liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. A control-flow timing lean has been identified in the reference implementation of the Kyber key encapsulation mechanism when it is compiled with Clang 15-18 for `-Os`, `-O1`, and other compilation options. A proof-of-concept local attack on the reference implementation leaks the entire ML-KEM 512 secret key in ~10 minutes using end-to-end decapsulation timing measurements. The issue has been fixed in version 0.10.1. As a possible workaround, some compiler options may produce vectorized code that does not leak secret information, however relying on these compiler options as a workaround may not be reliable.

## Affected Products

- open-quantum-safe — liboqs (< 0.10.1)

## References

- [CNA](https://github.com/open-quantum-safe/liboqs/security/advisories/GHSA-f2v9-5498-2vpp)
- [CNA](https://github.com/open-quantum-safe/liboqs/commit/982c762c242ef549c914891b47bf6e0ed6321f91)
- [CNA](https://github.com/pq-crystals/kyber/commit/9b8d30698a3e7449aeb34e62339d4176f11e3c6c)
- [CNA](https://github.com/open-quantum-safe/liboqs/blob/7eecda6095c003ddded7175a1ffdf35a2ce63ed5/src/kem/kyber/pqcrystals-kyber_kyber512_ref/poly.c#L166)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.52%
- **EPSS Percentile:** 42.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._