CVE-2025-55039Network attack vector

RPC traffic modification via unauthenticated AES-CTR

Published Oct 15, 2025 · Updated Oct 15, 2025

Cryptographic integrity failure in Apache Spark before 3.4.4 and 3.5.0 through 3.5.1 allows man-in-the-middle attackers to alter RPC traffic. When network crypto is enabled without an explicit cipher, AuthEngine selects AES/CTR/NoPadding, whose malleable ciphertext is not authenticated before RPC messages are processed. The issue is reachable only by an on-path attacker when spark.network.crypto.enabled is true while the cipher remains unset; altered heartbeats or application data can corrupt workflow integrity.

CVSS severity6.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic integrity failure in Apache Spark before 3.4.4 and 3.5.0 through 3.5.1 allows man-in-the-middle attackers to alter RPC traffic. When network crypto is enabled without an explicit cipher, AuthEngine selects AES/CTR/NoPadding, whose malleable ciphertext is not authenticated before RPC messages are processed. The issue is reachable only by an on-path attacker when spark.network.crypto.enabled is true while the cipher remains unset; altered heartbeats or application data can corrupt workflow integrity.

The record

CVE
CVE-2025-55039
Published
Oct 15, 2025
Updated
Oct 15, 2025
Vendor
The Apache Software Foundation
Product
Apache Spark
Classifications
CWE-326, CWE-347, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.4.4
  2. Affected versionversion=3.5.0 <3.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Sparkversion=0 <3.4.4; version=3.5.0 <3.5.2

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-326Inadequate Encryption Strength
CWE-347Improper Verification of Cryptographic Signature
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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