CVE-2026-32773: There is a lack of XSS escaping in the Spark History Server prior to 3.5.8 which allows a malicious Spark job

Routine

MEDIUM 6.1WATCHLISTUPGRADE

CVE-2026-32773 is a medium-severity flaw (CVSS 6.1) affecting spark. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

There is a lack of XSS escaping in the Spark History Server prior to 3.5.8 which allows a malicious Spark job to generate arbitrary unescaped frontend code which could lead to a minimal privilege escalation in browser. Users are encouraged to upgrade to Spark 3.5.8 or later. This CVE is marked as "low" since the path to exploit requires both relatively high permissions (ability to launch a Spark job) and requires tricking a user with higher perm

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-80
Published	2026-09-02
Last modified	2026-09-08

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

Last updated 2026-09-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-02 11:17 UTCPublished CVE record published
2026-09-08 13:04 UTCUpdated Record last modified

apache spark UPGRADE

Affected: >= 3.0.0 and < 3.5.8

Fixed in: 3.5.8

Safe to downgrade to: a release before 3.0.0

1. Check installed version

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

2. UPGRADE to 3.5.8 (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 3.0.0 (Debian / Ubuntu)

apt-cache madison spark sudo apt install spark=<VERSION_BEFORE_3.0.0> 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_3.0.0> 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-2026-32773?

spark: upgrade to 3.5.8. Exact commands for each OS are on this page.

Is CVE-2026-32773 being exploited?

CVE-2026-32773 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-2026-32773 affect?

CVE-2026-32773 affects spark. Severity is medium (CVSS 6.1). There is a lack of XSS escaping in the Spark History Server prior to 3.5.8 which allows a malicious Spark job to generate arbitrary unescaped frontend code which could lead to a minimal privilege escalation in browser. Users are encouraged

How urgent is CVE-2026-32773?

Priority 35/100. On your watchlist

Software pages

Apache Spark vulnerabilities

References

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