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Vulnerability record · CVE-2026-59646 · published 3 August 2026

CVE-2026-59646: Bouncycastle bc-java vulnerability

Bouncycastle · Bc Java

In Bouncy Castle for Java before 1.85, DTLS handshake reassembler allocates buffer from unchecked 24-bit length. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (2.1.X series).

8.7 CVSS 4.0 High EPSS 0.62% · top 52.6% CWE-789 · CWE-789
8.7CVSS 4.0 base score
0.62%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
3References
28 Aug 2026Last modified by NVD

Description

In Bouncy Castle for Java before 1.85, DTLS handshake reassembler allocates buffer from unchecked 24-bit length. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (2.1.X series).

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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:

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/bcgit/bc-java/commit/2d98721e71bbd822ffa0f84e088eea645cf679fa Patch
https://github.com/bcgit/bc-java/commit/2ea38942c7917f6d7ab4de93d8a5336d021df0d9 Patch
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059646 Third Party Advisory

Track CVE-2026-59646 inside VULONE

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-59646), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.