Patch tracker / CVE reference / CVE-2026-5598

CVE-2026-5598

Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules). This vulnerability is associated with program files FrodoEngine.Java. This issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84.

Risk summary

High

7.5

CVSS v3 base

High

Severity

Not listed

Actively exploited

High severity vulnerability, CVSS 7.5.

How to fix CVE-2026-5598 Admin questions

Senserva AI Opinion and rich prompt for CVE-2026-5598

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I am an IT admin assessing a vulnerability. Facts for CVE-2026-5598 (source: https://senserva.com/cve/CVE-2026-5598.html, data from CISA KEV and NVD, refreshed once a day (early morning US Central)):
- CVE-2026-5598: High severity vulnerability, CVSS 7.5
- Actively exploited (CISA KEV): no
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) What to patch or mitigate first. 4) How to check whether my devices are exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Schedule normally

No exploitation observed: not in the CISA KEV catalog, EPSS under 1%.

No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.

Do this now: Deploy with your normal update cycle. This page refreshes daily; the verdict changes the day the data does.

Updated September 11, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

How to fix CVE-2026-5598

Apply the patched version named in the vendor security advisory. Where a workaround exists, apply it only until the update is deployed, not as a substitute.

NVD detail

Common questions about CVE-2026-5598

Is CVE-2026-5598 actively exploited?

It is not currently listed in the CISA Known Exploited Vulnerabilities catalog. That can change: unexploited CVEs regularly get weaponized months after disclosure, which is why patching on your normal cadence matters.

What fixes CVE-2026-5598?

The authoritative fix is in the vendor security advisory. Apply the patched version listed there; the references below link to the CVE record and NVD detail.

Which products are affected by CVE-2026-5598?

See the vendor security advisory for the affected product list.

Can I ask my own AI about CVE-2026-5598?

Yes. This page includes a free, ready-to-paste AI prompt with CVE-2026-5598's key facts: severity, CVSS, CISA KEV status, and the affected products. Copy it into Claude, ChatGPT, or Copilot for a triage plan.

Scope and sources

Authoritative references: CVE record NVD detail

Every Microsoft CVE and the patches that fix it, ranked by real-world risk: the Microsoft Patch Tracker. The full searchable CVE reference: CVE and vulnerability management.