How severe is CVE-2021-42048?

CVE-2021-42048 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-42048 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42048?

CVE-2021-42048 affects Mediawiki. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42048?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-42048 published?

CVE-2021-42048 was published on 2022-09-29 and last updated on 2026-06-17.

CVE-2021-42048

CVE-2021-42048 is a medium-severity vulnerability in Mediawiki with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mediawiki
Published: 2022-09-29
Last modified: 2026-06-17

Description

An issue was discovered in the Growth extension in MediaWiki through 1.36.2. Any admin can add arbitrary JavaScript code to the Newcomer home page footer, which can be executed by viewers with zero edits.

Frequently asked questions

What is CVE-2021-42048?: An issue was discovered in the Growth extension in MediaWiki through 1.36.2. Any admin can add arbitrary JavaScript code to the Newcomer home page footer, which can be executed by viewers with zero edits.
How severe is CVE-2021-42048?: CVE-2021-42048 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-42048 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42048?: CVE-2021-42048 affects Mediawiki. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42048?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-42048 published?: CVE-2021-42048 was published on 2022-09-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*

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