How severe is CVE-2025-55039?

CVE-2025-55039 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2025-55039?

CVE-2025-55039 affects the following packages: org.apache.spark:spark-network-common_2.13 (Maven), org.apache.spark:spark-network-common_2.13 (Maven), org.apache.spark:spark-network-common_2.12 (Maven), org.apache.spark:spark-network-common_2.12 (Maven), pyspark (PyPI), pyspark (PyPI). Ecosystems affected: Maven, PyPI.

How do I fix CVE-2025-55039?

Update org.apache.spark:spark-network-common_2.13 to 3.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-55039 is resolved across your whole dependency graph.

How do I detect CVE-2025-55039 in my Maven, PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.spark:spark-network-common_2.13. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2025-55039 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2025-55039?

O3 pinpoints whether CVE-2025-55039 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2025-55039 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-55039 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-55039?

CVE-2025-55039 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 13th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2025-55039 published, and has it been updated?

CVE-2025-55039 was published on October 15, 2025 and was last updated on May 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven🐍 PyPI

CVE-2025-55039

MEDIUM

Apache Spark has Inadequate Encryption Strength

Also known asGHSA-6p6v-m64v-jx8qPYSEC-2025-184

Published

Oct 15, 2025

Updated

May 20, 2026

Affected

6 pkgs

Patched

6 / 6

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk13th percentile+0.13%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

6 pkgs affected

☕org.apache.spark:spark-network-common_2.13☕org.apache.spark:spark-network-common_2.13☕org.apache.spark:spark-network-common_2.12☕org.apache.spark:spark-network-common_2.12🐍pyspark🐍pyspark

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

6 total 6 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.spark:spark-network-common_2.13`	≥ 3.5.0&&< 3.5.2	3.5.2
☕Maven	`org.apache.spark:spark-network-common_2.13`	all versions	3.4.4
☕Maven	`org.apache.spark:spark-network-common_2.12`	all versions	3.4.4
☕Maven	`org.apache.spark:spark-network-common_2.12`	≥ 3.5.0&&< 3.5.2	3.5.2
🐍PyPI	`pyspark`	all versions	3.4.4
🐍PyPI	`pyspark`	≥ 3.5.0&&< 3.5.2	3.5.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.spark:spark-network-common_2.13. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.apache.spark:spark-network-common_2.13 to 3.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-55039 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-55039 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2025-55039. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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, pote

O3 Security · Impact-Aware SCA

Is CVE-2025-55039 in your dependencies?

O3 detects CVE-2025-55039 across Maven, PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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