CVE-2026-48954: Improper validation leads to a generic XSS vector in the language override feature.

Routine

MEDIUM 6.1UPGRADE

CVE-2026-48954 is a medium-severity flaw (CVSS 6.1) affecting joomla\!. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper validation leads to a generic XSS vector in the language override feature.

Why this priority

No elevated risk signals yet

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	0.2% (top 85%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-07-07
Last modified	2026-10-25

Publisher (CNA): Joomla! Project · Vendor: joomla

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-07 19:16 UTCPublished CVE record published
2026-10-25 20:10 UTCUpdated Record last modified

joomla joomla\! UPGRADE

Affected: >= 3.0.0 and < 5.4.7 · >= 6.0.0 and < 6.1.2

Fixed in: 5.4.7, 6.1.2

Safe to downgrade to: a release before 3.0.0

1. Check installed version

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

2. UPGRADE to 5.4.7 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade joomla

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 joomla sudo apt install joomla=<VERSION_BEFORE_3.0.0> sudo apt-mark hold joomla

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

dnf --showduplicates list joomla sudo dnf downgrade joomla-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add joomla

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-2026-48954?

joomla\!: upgrade to 5.4.7, 6.1.2. Exact commands for each OS are on this page.

Is CVE-2026-48954 being exploited?

CVE-2026-48954 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-2026-48954 affect?

CVE-2026-48954 affects joomla\!. Severity is medium (CVSS 6.1). Improper validation leads to a generic XSS vector in the language override feature.

How urgent is CVE-2026-48954?

Priority 25/100. No elevated risk signals yet.

Software pages

Joomla vulnerabilities

Related CVEs

CVE-2026-48958 HIGH 8.8 UPGRADE An improper access check allows unauthorized users to create custom fields via webservices endpoints.
CVE-2026-48948 HIGH 8.8 UPGRADE An improper access check allows user to download vcard exports of com_contact contacts that are inaccessible.
CVE-2026-48957 HIGH 8.8 UPGRADE An improper access check allows unauthorized users to access com_privacy datasets.
CVE-2026-48955 MEDIUM 6.5 UPGRADE An improper access check allows unauthorized users to access workflow stage and transition information.
CVE-2026-48949 MEDIUM 6.1 UPGRADE Lack of validation leads to an XSS vulnerability in the MFA management views.

References

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