Vulnerability in Bouncycastle Bc-Java

CVE-2024-14041

In Bouncy Castle for Java from 1.73 to before 1.78, three ML-KEM (CRYSTALS-Kyber) routines divided secret-derived polynomial coefficients by the modulus q: Poly.toMsg, which decodes the decrypted message, and the ciphertext compression routines Poly.compressPoly and PolyVec.compressPolyVec. An attacker able to measure the timing of a large number of decapsulations performed with the same long-term private key can recover that key. These are the KyberSlash1 (Poly.toMsg) and KyberSlash2 (ciphertext compression) divisions. Compression performed during encapsulation operates on values that become the public ciphertext and is not affected.

EPSS: 0.003 (27.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2024-14041?
CVE-2024-14041 is a medium-severity vulnerability in Bouncycastle Bc-Java, classified under CWE-208. CVSS score: 5.9/10. Published 2026-07-28.
How severe is CVE-2024-14041?
Medium severity. CVSS v3 base score is 5.9 out of 10.