Improper Validation of Integrity Check Value in Bouncy Castle

Exploitation

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

CVSS

4.4 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

EPSS

• CVE-2018-5382: 0.26% estimated exploitation activity in the next 30 days; percentile 17.85 (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 default BKS keystore use an HMAC that is only 16 bits long, which can allow an attacker to compromise the integrity of a BKS keystore. Bouncy Castle release 1.47 changes the BKS format to a format which uses a 160 bit HMAC instead. This applies to any BKS keystore generated prior to BC 1.47. For situations where people need to create the files for legacy reasons a specific keystore type "BKS-V1" was introduced in 1.49. It should be noted that the use of "BKS-V1" is discouraged by the library authors and should only be used where it is otherwise safe to do so, as in where the use of a 16 bit checksum for the file integrity check is not going to cause a security issue in itself.

Published by the source

13 May 2022, 01:01 UTC

Last modified by the source

27 Jan 2023, 05:02 UTC

Source last checked

26 Oct 2026, 15:53 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8477-3v39-ggpm

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# Patch Next advisory brief: CVE-2018-5382

Advisory: Improper Validation of Integrity Check Value in Bouncy Castle
IDs: CVE-2018-5382, GHSA-8477-3v39-ggpm
Record: https://patchnext.com/advisories/cve-2018-5382 (revision 1, source checked 26 Oct 2026, 15:53 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.bouncycastle:bcprov-jdk15on 1.50. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.bouncycastle:bcprov-jdk15on: affected < 1.50; fixed in 1.50

## Suggested inspection (read-only)
- Maven org.bouncycastle:bcprov-jdk15on: 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:bcprov-jdk15on.
- 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-8477-3v39-ggpm (GitHub-reviewed advisory GHSA-8477-3v39-ggpm lists affected ranges: Maven org.bouncycastle:bcprov-jdk15on >=0 <1.50)

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