How severe is CVE-2021-42043?

CVE-2021-42043 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-42043 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42043?

CVE-2021-42043 affects Mediawiki. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42043?

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

When was CVE-2021-42043 published?

CVE-2021-42043 was published on 2021-10-06 and last updated on 2026-06-17.

CVE-2021-42043

CVE-2021-42043 is a medium-severity vulnerability in Mediawiki with a CVSS 3.x base score of 6.1. 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 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mediawiki
Published: 2021-10-06
Last modified: 2026-06-17

Description

An issue was discovered in Special:MediaSearch in the MediaSearch extension in MediaWiki through 1.36.2. The suggestion text (a parameter to mediasearch-did-you-mean) was not being properly sanitized and allowed for the injection and execution of HTML and JavaScript via the intitle: search operator within the query.

Frequently asked questions

What is CVE-2021-42043?: An issue was discovered in Special:MediaSearch in the MediaSearch extension in MediaWiki through 1.36.2. The suggestion text (a parameter to mediasearch-did-you-mean) was not being properly sanitized and allowed for the injection and execution of HTML and JavaScript via the intitle: search operator within the query.
How severe is CVE-2021-42043?: CVE-2021-42043 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-42043 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42043?: CVE-2021-42043 affects Mediawiki. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42043?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-42043 published?: CVE-2021-42043 was published on 2021-10-06 and last updated on 2026-06-17.

References

Affected products (1)

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

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