Legion of the Bouncy Castle Java Cryptography API Bleichenbacher Oracle Vulnerability

Exploitation

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

CVSS

not scored

EPSS

• CVE-2007-6721: 2.41% estimated exploitation activity in the next 30 days; percentile 84.14 (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.

The Legion of the Bouncy Castle Java Cryptography API before release 1.38, as used in Crypto Provider Package before 1.36, has unknown impact and remote attack vectors related to "a Bleichenbacher vulnerability in simple RSA CMS signatures without signed attributes."

Published by the source

1 May 2022, 18:45 UTC

Last modified by the source

21 Sep 2023, 22:46 UTC

Source last checked

26 Oct 2026, 16:12 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m26p-m559-g5j5

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# Patch Next advisory brief: CVE-2007-6721

Advisory: Legion of the Bouncy Castle Java Cryptography API Bleichenbacher Oracle Vulnerability
IDs: CVE-2007-6721, GHSA-m26p-m559-g5j5
Record: https://patchnext.com/advisories/cve-2007-6721 (revision 1, source checked 26 Oct 2026, 16:12 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: bouncycastle:bcprov-jdk14 1.38; bouncycastle:bcprov-jdk15 1.38; bouncycastle:bcprov-jdk16 1.38. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven bouncycastle:bcprov-jdk14: affected < 1.38; fixed in 1.38
- Maven bouncycastle:bcprov-jdk15: affected < 1.38; fixed in 1.38
- Maven bouncycastle:bcprov-jdk16: affected < 1.38; fixed in 1.38

## Suggested inspection (read-only)
- Maven bouncycastle:bcprov-jdk14: check the installed version with your package manager.
- Maven bouncycastle:bcprov-jdk15: check the installed version with your package manager.
- Maven bouncycastle:bcprov-jdk16: 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 bouncycastle:bcprov-jdk14, bouncycastle:bcprov-jdk15, bouncycastle:bcprov-jdk16.
- 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://github.com/advisories/GHSA-m26p-m559-g5j5 (GitHub-reviewed advisory GHSA-m26p-m559-g5j5 lists affected ranges: Maven bouncycastle:bcprov-jdk14 >=0 =0 =0 <1.38)

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