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MinaApplication · Apache

CVE-2026-42779

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-01
Fix available
A fix is available. Upgrade to 2.1.12 / 2.2.7 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

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
The fix for CVE-2026-41635 was not applied to the 2.1.X and 2.2.X branches. Here was the original issue description: Apache MINA's AbstractIoBuffer.resolveClass() contains two branches, one of them (for static classes or primitive types) does not check the class at all, bypassing the classname allowlist and allowing arbitrary code to be executed. The fix checks if the class is present in the accepted class filter before calling Class.forName(). Affected versions are Apache MINA 2.1.0 <= 2.1.11, and 2.2.0 <= 2.2.6. The problem is resolved in Apache MINA 2.1.12, and 2.2.7 by applying the classname allowlist earlier. Affected are applications using Apache MINA that call IoBuffer.getObject(). Applications using Apache MINA are advised to upgrade.

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

Apache MINA's AbstractIoBuffer.resolveClass() contains a deserialization flaw where one branch (handling static classes or primitive types) completely bypasses the classname allowlist, enabling arbitrary code execution via Class.forName() without validation. This vulnerability was introduced because the fix for CVE-2026-41635 was not applied to the 2.1.X and 2.2.X branches.

MitigationUpgrade to Apache MINA 2.1.12 or 2.2.7, or manually apply classname allowlist validation before Class.forName() calls in all branches of AbstractIoBuffer.resolveClass().

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MinaApplication
Affected:>= 2.1.0, < 2.1.12>= 2.2.0, < 2.2.7

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
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Identify Apache MINA version in your deployment
    Check your project's dependency management (Maven pom.xml, Gradle build.gradle, or the mina-core.jar MANIFEST.MF file) for the mina-core artifact version
    Affected if The version is >= 2.1.0 and < 2.1.12, or >= 2.2.0 and < 2.2.7
  2. Confirm MINA IoBuffer deserialization is in use
    Search your codebase for usages of IoBuffer.getObject(), IoBuffer.wrap(), or custom ObjectInput/ObjectReader implementations that deserialize IoBuffer payloads from untrusted sources
    Affected if Your application deserializes IoBuffer objects containing arbitrary data from network sources or user input
  3. Check if custom class resolution is configured
    Inspect your IoBuffer configuration and any custom ObjectInput implementations for calls to AbstractIoBuffer.setClassResolver() or similar custom deserialization logic
    Affected if Custom class resolution is used without an explicit allowlist, allowing the vulnerable code path in resolveClass() to execute
  4. Verify Java serialization of IoBuffer occurs
    Review network protocol handlers or message parsers that use IoBuffer.putObject()/getObject() to serialize/deserialize objects, especially with data from external sources
    Affected if Objects are serialized into IoBuffer and retrieved via getObject() from untrusted streams, enabling the bypassed allowlist branch to be triggered

You are affected if your deployed Apache MINA version is 2.1.0-2.1.11 or 2.2.0-2.6 and your application deserializes IoBuffer objects from untrusted sources without additional classname allowlisting.

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
Upgrade available Upgrade to 2.1.12 / 2.2.7 or later
Fixed in 2.1.122.2.7
Vendor patch lists.apache.org →
Interim mitigation

Upgrade to Apache MINA 2.1.12 or 2.2.7, or manually apply classname allowlist validation before Class.forName() calls in all branches of AbstractIoBuffer.resolveClass().

Recommended fix High confidence

Apache MINA 2.1.12 or 2.2.7 (depending on which branch you are on)

  1. Identify the current Apache MINA version in use by checking project dependencies (e.g., pom.xml for Maven, build.gradle for Gradle)
  2. If using a 2.1.x version (>= 2.1.0, < 2.1.12), update the dependency to version 2.1.12
  3. If using a 2.2.x version (>= 2.2.0, < 2.2.7), update the dependency to version 2.2.7
  4. For Maven, update the version in pom.xml: change <version> to 2.1.12 or 2.2.7 accordingly
  5. For Gradle, update the version in build.gradle: change the mina-core dependency version to 2.1.12 or 2.2.7
  6. Rebuild and test the application to verify the upgrade works correctly

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

Fix this in Mina Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

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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-2026-42779 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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