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SparkApplication · Apache

CVE-2025-55039

MEDIUM · 6.5 CVSS v3.1 Published 2025-10-15
Fix available
A fix is available. Upgrade to 3.4.4 / 3.5.2 or later.
See remediation →
74/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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
This issue affects Apache Spark versions before 3.4.4, 3.5.2 and 4.0.0. Apache Spark versions before 4.0.0, 3.5.2 and 3.4.4 use an insecure default network encryption cipher for RPC communication between nodes. When spark.network.crypto.enabled is set to true (it is set to false by default), but spark.network.crypto.cipher is not explicitly configured, Spark defaults to AES in CTR mode (AES/CTR/NoPadding), which provides encryption without authentication. This vulnerability allows a man-in-the-middle attacker to modify encrypted RPC traffic undetected by flipping bits in ciphertext, potentially compromising heartbeat messages or application data and affecting the integrity of Spark workflows. To mitigate this issue, users should either configure spark.network.crypto.cipher to AES/GCM/NoPadding to enable authenticated encryption or enable SSL encryption by setting spark.ssl.enabled to true, which provides stronger transport security.

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 Spark versions before 3.4.4, 3.5.2, and 4.0.0 use an insecure default cipher (AES/CTR/NoPadding) when spark.network.crypto.enabled is true but spark.network.crypto.cipher is not explicitly set. CTR mode provides encryption without authentication, allowing a MITM attacker to flip bits in ciphertext and modify RPC traffic (including heartbeats and application data) without detection.

MitigationSet spark.network.crypto.cipher to AES/GCM/NoPadding to enable authenticated encryption, or alternatively enable SSL encryption by setting spark.ssl.enabled to true for stronger transport security.

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
SparkApplication
Affected:< 3.4.4>= 3.5.0, < 3.5.2

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
Low
Integrity
Low
Availability
None

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

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. Check Spark version
    Run spark-submit --version or check the installed Spark version in your cluster. Compare against affected ranges: < 3.4.4, >= 3.5.0 and < 3.5.2, or 4.0.0
    Affected if Version is in any of the affected ranges (< 3.4.4, >= 3.5.0 and < 3.5.2, or 4.0.0)
  2. Check if network crypto is enabled
    Inspect Spark configuration files (spark-defaults.conf, spark-env.sh) or runtime config for spark.network.crypto.enabled set to true
    Affected if spark.network.crypto.enabled is true
  3. Check if custom cipher is configured
    Inspect Spark configuration for spark.network.crypto.cipher setting. If not explicitly set, the default insecure AES/CTR/NoPadding cipher is used
    Affected if spark.network.crypto.cipher is not set or is set to a non-AES/GCM/NoPadding value

You are affected if running a vulnerable Spark version with spark.network.crypto.enabled=true and without an explicit spark.network.crypto.cipher configuration set to AES/GCM/NoPadding

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 3.4.4 / 3.5.2 or later
Fixed in 3.4.43.5.2
Interim mitigation

Set spark.network.crypto.cipher to AES/GCM/NoPadding to enable authenticated encryption, or alternatively enable SSL encryption by setting spark.ssl.enabled to true for stronger transport security.

Recommended fix High confidence

Upgrade to Spark 3.4.4+ (for 3.4.x line) or Spark 3.5.2+ (for 3.5.x line). Versions 4.0.0+ are also fixed.

  1. 1. Identify the current Apache Spark version by running: spark-submit --version or checking your cluster management console
  2. 2. If running Spark < 3.4.4: Upgrade to Spark 3.4.4 or later (e.g., 3.4.5) which contains the fix
  3. 3. If running Spark 3.5.0 or 3.5.1: Upgrade to Spark 3.5.2 or later (e.g., 3.5.4) which contains the fix
  4. 4. If running Spark >= 4.0.0: No upgrade needed as these versions are already fixed
  5. 5. After upgrading, verify the fix by confirming spark.network.crypto.cipher defaults to a secure authenticated encryption mode or that you are using SSL (spark.ssl.enabled=true)
  6. 6. Alternatively, if upgrade is not immediately feasible, configure spark.network.crypto.cipher=AES/GCM/NoPadding in spark-defaults.conf or spark-site.xml to enable authenticated encryption
  7. 7. Alternatively, enable SSL encryption by setting spark.ssl.enabled=true in your configuration
Caveat Minimal risk - the fix is backward compatible; however, ensure any custom RPC configurations are tested after upgrade. GCM mode may have slightly different performance characteristics than CTR mode.

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

Fix this in Spark Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
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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-2025-55039 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data