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Vulnerability record · CVE-2026-59641 · published 3 August 2026

CVE-2026-59641: Bouncycastle bc-java insufficient verification of data authenticity vulnerability

Bouncycastle · Bc Java

In Bouncy Castle for Java before 1.85, S/MIME validator trusts signer-asserted signingTime for path validation. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcmail-fips and bcjmail-fips 1.0.7 (1.0.X series), 2.0.7 (2.0.X series) and 2.1.7 (2.1.X series).

8.7 CVSS 4.0 High EPSS 0.20% · top 90.6% CWE-345 · Insufficient verification of data authenticity
8.7CVSS 4.0 base score
0.20%EPSS exploitation probability, 30 days
NoNot in CISA KEV
4Affected product versions listed by NVD
3References
28 Aug 2026Last modified by NVD

Description

In Bouncy Castle for Java before 1.85, S/MIME validator trusts signer-asserted signingTime for path validation. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcmail-fips and bcjmail-fips 1.0.7 (1.0.X series), 2.0.7 (2.0.X series) and 2.1.7 (2.1.X series).

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

Affected products

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

References

LinkTags
https://github.com/bcgit/bc-java/commit/2f81b22d559b3a1b026388e1ca78dd547384def8 Patch
https://github.com/bcgit/bc-java/commit/fd89fe918b37fea1c71e95fae50284a325b09721 Patch
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059641 Third Party Advisory

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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-2026-59641), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.