CVE-2024-55488: A stored cross-site scripting (XSS) vulnerability in Umbraco CMS v14.3.1 allows attackers to execute arbitrary

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MEDIUM 6.5REMOTEDOWNGRADE

CVE-2024-55488 is a medium-severity flaw (CVSS 6.5) affecting umbraco cms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A stored cross-site scripting (XSS) vulnerability in Umbraco CMS v14.3.1 allows attackers to execute arbitrary web scripts or HTML via a crafted payload. NOTE: This has been disputed by the vendor since this potential attack is only possible via authenticated users who have been manually allowed access to the CMS. There was a deliberate decision made not to apply HTML sanitization at the product level.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-79
Published	2025-01-22
Last modified	2026-07-05

Publisher (CNA): MITRE · Vendor: umbraco

Last updated 2026-07-05 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-01-22 16:15 UTCPublished CVE record published
2026-07-05 15:16 UTCUpdated Record last modified

umbraco umbraco cms DOWNGRADE

Affected: 14.3.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 14.3.1

1. Check installed version

apt-cache policy umbraco-cms || rpm -q umbraco-cms || umbraco-cms --version

2. No fixed release: DOWNGRADE to a release before 14.3.1 (Debian / Ubuntu)

apt-cache madison umbraco-cms sudo apt install umbraco-cms=<VERSION_BEFORE_14.3.1> sudo apt-mark hold umbraco-cms

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list umbraco-cms sudo dnf downgrade umbraco-cms-<VERSION_BEFORE_14.3.1> sudo dnf versionlock add umbraco-cms

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-2024-55488?

umbraco cms: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2024-55488 being exploited?

CVE-2024-55488 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-2024-55488 affect?

CVE-2024-55488 affects umbraco cms. Severity is medium (CVSS 6.5). A stored cross-site scripting (XSS) vulnerability in Umbraco CMS v14.3.1 allows attackers to execute arbitrary web scripts or HTML via a crafted payload. NOTE: This has been disputed by the vendor since this potential attack is only possibl

How urgent is CVE-2024-55488?

Priority 39/100. Public exploit reference; Remotely exploitable, no login, no user action

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References

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