Cyber Resilience

CVE-2026-59644

DoS in Bouncycastle Bc-Java ≤ 1.85

Published
03 August 2026
Modified
31 August 2026
Patch / advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS: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:X/V:X/RE:X/U:Amber
EPSS Score 0.0031 24th percentile
Risk Priority 44 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-59644 is a high-severity Excessive Iteration (CWE-834) vulnerability in Bouncycastle Bc-Java. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-8 (Security and Privacy Engineering Principles) and SC-6 (Resource Availability) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In Bouncy Castle for Java before 1.85, MLS hash-ratchet honours arbitrary 32-bit generation counter from sender.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-12852Same product: Bouncycastle Bc-Java
CVE-2026-59652Same product: Bouncycastle Bc-Java
CVE-2023-33201Same product: Bouncycastle Bc-Java
CVE-2026-12185Same product: Bouncycastle Bc-Java
CVE-2024-14041Same product: Bouncycastle Bc-Java
CVE-2026-59646Same product: Bouncycastle Bc-Java
CVE-2026-58059Same product: Bouncycastle Bc-Java
CVE-2026-59649Same product: Bouncycastle Bc-Java
CVE-2026-58060Same product: Bouncycastle Bc-Java
CVE-2026-14682Same product: Bouncycastle Bc-Java

Affected Assets

bouncycastle
bc-java
≤ 1.85

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Engineering principles can require developers to bound all loops and iterations at design time.

Resource quotas limit the CPU/time impact of an excessively long loop without eliminating the flaw.

Input validation can reject or sanitize data that would otherwise drive unbounded iteration.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
prevents

Secure SDLC practices directly prevent unbounded loops via code review, static analysis, and testing.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure development lifecycle requires input validation and loop bounds, directly limiting excessive iteration.

prevents

Application security requirements include resource-consumption limits that prevent unbounded loops.

prevents

Secure architecture principles mandate defensive coding patterns such as loop termination checks.

prevents

Secure coding standards explicitly forbid unbounded loops and require explicit iteration limits.

finds

Security testing can detect excessive iteration through stress and fuzz testing.

References