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CWE-354Weakness · CWE-354

CVE-2026-59642

HIGH · 8.7 CVSS v4.0 Published 2026-08-03
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
96/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available 3 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In Bouncy Castle for Java before 1.85, CMS AuthenticatedData content not bound to MAC when authAttrs present. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In Bouncy Castle for Java, the CMS AuthenticatedData implementation fails to properly bind the message content to the Message Authentication Code (MAC) when authenticated attributes (authAttrs) are present. This allows attackers to potentially replace or modify the content while keeping a valid MAC, bypassing authentication integrity checks.

MitigationUpgrade Bouncy Castle Java library to version 1.85+, LTS 2.73.12+, or the appropriate FIPS version (bcpkix-fips 1.0.12+, 2.0.12+, or 2.1.12+) to resolve the MAC binding vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate Bouncy Castle Java library in the environment
    Search for bcprov*.jar, bcpkix*.jar, or bouncycastle dependencies in application classpaths, lib folders, Maven/Gradle dependencies, or container images
    Affected if Bouncy Castle Java library is present in the environment
  2. Determine the installed Bouncy Castle version
    Inspect the MANIFEST.MF file inside the bcprov*.jar or bcpkix*.jar for the Implementation-Version attribute, or check the dependency declaration in build files (pom.xml, build.gradle)
    Affected if The version cannot be determined or is below 1.85 for non-LTS, below 2.73.12 for LTS 2.x, below 1.0.12/2.0.12/2.1.12 for FIPS variants
  3. Identify CMS AuthenticatedData usage with authAttrs
    Review application code for org.bouncycastle.cms.CMSAuthenticatedData usage, specifically look for calls to addAuthAttributes() or AuthenticatedDataGenerator that include authentication attributes
    Affected if The application processes CMS AuthenticatedData messages that include authentication attributes (authAttrs)
  4. Compare installed version to fixed releases
    Cross-reference the identified version against the known fixed versions: 1.85+, LTS 2.73.12+, bcpkix-fips 1.0.12+, 2.0.12+, or 2.1.12+
    Affected if The installed version is below the corresponding fixed version for the detected product line

The environment is affected if it runs a Bouncy Castle Java version below the fixed releases AND processes CMS AuthenticatedData that includes authentication attributes.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch github.com →
Interim mitigation

Upgrade Bouncy Castle Java library to version 1.85+, LTS 2.73.12+, or the appropriate FIPS version (bcpkix-fips 1.0.12+, 2.0.12+, or 2.1.12+) to resolve the MAC binding vulnerability.

Recommended fix High confidence

Bouncy Castle Java: 1.85+, 2.73.12+ (LTS) | BC-FIPS: bcpkix-fips 1.0.12+, 2.0.12+, or 2.1.12+ depending on series

  1. 1. Identify the current Bouncy Castle for Java library version in your project by checking your dependency management system (Maven pom.xml, Gradle build.gradle, or equivalent)
  2. 2. Determine which Bouncy Castle variant you are using: bouncy-castle (non-FIPS), bouncy-castle-provider (BC-FIPS), or bouncy-castle-fips (BC-FJA)
  3. 3. For non-FIPS users: upgrade to version 1.85 or later (or 2.73.12 or later for LTS)
  4. 4. For BC-FIPS users on 1.0.X series: upgrade to bcpkix-fips version 1.0.12 or later
  5. 5. For BC-FIPS users on 2.0.X series: upgrade to bcpkix-fips version 2.0.12 or later
  6. 6. For BC-FIPS users on 2.1.X series: upgrade to bcpkix-fips version 2.1.12 or later
  7. 7. Update your dependency manager (mvn clean install or gradle build) to pull the new version
  8. 8. Rebuild and run your application's test suite to verify compatibility
Caveat Major version upgrades may introduce API changes; review BC release notes for any deprecated methods or behavioral changes

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the patch applied

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-59642 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data