CVE-2025-55039: This issue affects Apache Spark versions before 3.4.4, 3.5.2 and 4.0.0. Apache Spark versions before 4.0.0

Routine

MEDIUM 6.5REMOTEWATCHLISTUPGRADE

CVE-2025-55039 is a medium-severity flaw (CVSS 6.5) affecting spark. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 a

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Weakness	CWE-326, CWE-347
Published	2025-10-15
Last modified	2026-10-08

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-10-15 08:15 UTCPublished CVE record published
2026-10-08 12:10 UTCUpdated Record last modified

apache spark UPGRADE

Affected: < 3.4.4 · >= 3.5.0 and < 3.5.2

Fixed in: 3.4.4, 3.5.2

Safe to downgrade to: a release before 3.5.0

1. Check installed version

apt-cache policy spark || rpm -q spark || spark --version

2. UPGRADE to 3.4.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade spark

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade spark

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.5.0 (Debian / Ubuntu)

apt-cache madison spark sudo apt install spark=<VERSION_BEFORE_3.5.0> sudo apt-mark hold spark

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list spark sudo dnf downgrade spark-<VERSION_BEFORE_3.5.0> sudo dnf versionlock add spark

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-55039?

spark: upgrade to 3.4.4, 3.5.2. Exact commands for each OS are on this page.

Is CVE-2025-55039 being exploited?

CVE-2025-55039 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-55039 affect?

CVE-2025-55039 affects spark. Severity is medium (CVSS 6.5). 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.crypt

How urgent is CVE-2025-55039?

Priority 35/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Apache Spark vulnerabilities

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References

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