CVE-2024-14041
ML-KEM (Kyber) decapsulation leaks private key information through non-constant-time division in message decoding and ciphertext compression (KyberSlash)
Description
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.
INFO
Published Date :
July 28, 2026, 8:17 a.m.
Last Modified :
Aug. 26, 2026, 5:11 p.m.
Remotely Exploit :
Yes !
Source :
91579145-5d7b-4cc5-b925-a0262ff19630
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | 91579145-5d7b-4cc5-b925-a0262ff19630 | ||||
| CVSS 4.0 | HIGH | 91579145-5d7b-4cc5-b925-a0262ff19630 |
Solution
- Update Bouncy Castle to version 1.78 or later.
- Apply patches for the identified ML-KEM routines.
- Avoid timing measurements during decapsulation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2024-14041.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-14041 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-14041
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2024-14041 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-14041 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 26, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Added CPE Configuration OR *cpe:2.3:a:bouncycastle:bc-java:*:*:*:*:*:*:*:* versions from (including) 1.73 up to (excluding) 1.78 Added Reference Type bcorg: https://github.com/bcgit/bc-java/commit/1590247178f2280defa36421475f015175dfbe9e Types: Patch Added Reference Type bcorg: https://github.com/bcgit/bc-java/commit/5adb2c5c5b462a332b01a012bea0784b40b904e5 Types: Patch Added Reference Type bcorg: https://github.com/bcgit/bc-java/wiki/CVE-2024-14041 Types: Vendor Advisory Added Reference Type bcorg: https://kyberslash.cr.yp.to/ Types: Exploit -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 28, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2024-14041', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-28T12:54:52.417865Z'} -
New CVE Received by 91579145-5d7b-4cc5-b925-a0262ff19630
Jul. 28, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/bcgit/bc-java', 'vendor': 'Legion of the Bouncy Castle Inc.', 'modules': ['core'], 'product': 'BC-JAVA', 'versions': [{'status': 'affected', 'version': '1.73', 'lessThan': '1.78', 'versionType': 'maven'}], 'platforms': ['all'], 'packageURL': 'pkg:maven/org.bouncycastle/bcprov-jdk18on', 'packageName': 'bcprov', 'programFiles': ['Poly', 'PolyVec'], 'collectionURL': 'https://www.bouncycastle.org/download/bouncy-castle-java/', 'defaultStatus': 'unaffected'}] Added Description 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. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber Added CWE CWE-208 Added Reference https://github.com/bcgit/bc-java/commit/1590247178f2280defa36421475f015175dfbe9e Added Reference https://github.com/bcgit/bc-java/commit/5adb2c5c5b462a332b01a012bea0784b40b904e5 Added Reference https://github.com/bcgit/bc-java/wiki/CVE-2024-14041 Added Reference https://kyberslash.cr.yp.to/