CVE-2026-8798: Bouncy Castle Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-v6w3-qrh8-qccc
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CWE-835
Published
Advisory Summary

CVE-2026-8798 is a HIGH remote code execution vulnerability (CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')) affecting Bouncy Castle libraries in the Maven ecosystem. The issue involves the native entropy source used on intel platforms retried the cpu entropy instructions without any bound. Remediation is available by upgrading affected packages to version 2.1.3.

CVE-2026-8798 at a Glance

CVE Identifier CVE-2026-8798
GHSA Identifier GHSA-v6w3-qrh8-qccc
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')
Affected Product Bouncy Castle
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-8798

To remediate this vulnerability, upgrade all affected Bouncy Castle dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.bouncycastle:bc-fips fixed: 2.1.3 
<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bc-fips</artifactId>
    <version>2.1.3</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.bouncycastle

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-8798, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.bouncycastle

Analyze the terminal output to locate any version of Bouncy Castle in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.1.3), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.bouncycastle command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop'), where the product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. In Bouncy Castle, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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 exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected.

CVE-2026-8798 Affected Bouncy Castle Versions

1 component(s)
Fixed Versions:
2.1.3
Product / Package Ecosystem Affected Versions Fixed Version
org.bouncycastle:bc-fips
maven/org.bouncycastle/bc-fips
Maven
≥ 2.1.0
< 2.1.3
2.1.3

References

NVD — CVE-2026-8798 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-8798
Bouncy Castle Source Repository REPOSITORY
https://github.com/bcgit/bc-java
GitHub Advisory / Wiki ADVISORY
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908798

Frequently Asked Questions

What is CVE-2026-8798?
CVE-2026-8798 is a security vulnerability in Bouncy Castle involving the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop').
Which Bouncy Castle versions are affected?
Affected versions include releases prior to 2.1.3 across affected packages: org.bouncycastle:bc-fips.
What version fixes CVE-2026-8798?
Upgrading to 2.1.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is bc-fips affected?
Yes, org.bouncycastle:bc-fips is affected in releases prior to 2.1.3. Upgrade your dependency to 2.1.3 or later.
What CWE is associated with CVE-2026-8798?
CVE-2026-8798 is classified under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') (The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.).
How can I check Maven dependencies for CVE-2026-8798?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.bouncycastle'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-v6w3-qrh8-qccc",
  "modified" : "2026-09-18T17:37:11Z",
  "published" : "2026-08-08T03:31:12Z",
  "aliases" : [ "CVE-2026-8798" ],
  "summary" : "Bouncy Castle: the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound",
  "details" : "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 exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.bouncycastle:bc-fips"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.1.0"
      }, {
        "fixed" : "2.1.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-8798"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/bcgit/bc-java"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908798"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-835" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-18T17:37:11Z",
    "nvd_published_at" : "2026-08-08T01:16:31Z"
  }
}