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Fencer Vulns
medium 5.9

CVE-2024-36405 json

Control-flow timing leak in Kyber reference implementation when compiled with Clang 15-18 for -Os, -O1 and other options

published 2024-06-10 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-36062

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

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.

Patch / fix

  • openquantumsafe liboqs 0.10.1
  • oqs-provider SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 0.7.0-150600.3.3.1
  • liboqs SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 0.12.0-150600.3.3.1

suse advisories SUSE-SU-2025:0005-1

  • liboqs openSUSE Tumbleweed 0.10.1-1.1

opensuse advisories openSUSE-SU-2024:14039-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-36405 updated cvss 5.9

liboqs: leaks the entire ML-KEM 512 secret key

  • Red Hat Enterprise Linux 10 liboqs
    affected: no fix available

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • open-quantum-safe liboqs
  • open_quantum_safe liboqs

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.