Bouncy Castle: the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · 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/U:Amber · score source

EPSS

• CVE-2026-8798: 0.43% estimated exploitation activity in the next 30 days; percentile 37.10 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

In Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.1.3, the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound. RDSEED and RDRAND report failure through their carry flag, and the JNI seeding routine spun re-issuing the instruction for as long as that flag stayed clear, so a persistent failure of the on-chip entropy source - whether from a hardware fault, from the underlying DRBG being exhausted by contention across many cores, or from a hypervisor that does not provide the instruction - left the calling thread looping indefinitely inside the JNI call, where it could be neither interrupted nor timed out. Any operation drawing from the native entropy source could therefore hang, denying service to the application. The retry loops are now bounded (200 attempts for RDSEED and 20 for RDRAND, twice the baselines given in Intel's Digital Random Number Generator software implementation guide), pausing between attempts and, on…

Published by the source

8 Aug 2026, 03:31 UTC

Last modified by the source

18 Sep 2026, 17:45 UTC

Source last checked

26 Oct 2026, 16:55 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-v6w3-qrh8-qccc

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-v6w3-qrh8-qccc

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# Patch Next advisory brief: CVE-2026-8798

Advisory: Bouncy Castle: the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound
IDs: CVE-2026-8798, GHSA-v6w3-qrh8-qccc
Record: https://patchnext.com/advisories/cve-2026-8798 (revision 3, source checked 26 Oct 2026, 16:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.bouncycastle:bc-fips 2.1.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.bouncycastle:bc-fips: affected >= 2.1.0, < 2.1.3; fixed in 2.1.3

## Suggested inspection (read-only)
- Maven org.bouncycastle:bc-fips: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.bouncycastle:bc-fips.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-v6w3-qrh8-qccc (OSV record GHSA-v6w3-qrh8-qccc lists affected ranges: Maven org.bouncycastle:bc-fips >=2.1.0 <2.1.3 (fixed))
- Verified: https://github.com/advisories/GHSA-v6w3-qrh8-qccc (GitHub-reviewed advisory GHSA-v6w3-qrh8-qccc lists affected ranges: Maven org.bouncycastle:bc-fips >=2.1.0 <2.1.3)

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