How severe is CVE-2021-30155?

CVE-2021-30155 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-30155 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30155?

CVE-2021-30155 primarily affects Mediawiki. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30155?

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

When was CVE-2021-30155 published?

CVE-2021-30155 was published on 2021-04-09 and last updated on 2026-06-17.

CVE-2021-30155

CVE-2021-30155 is a medium-severity vulnerability in Mediawiki with a CVSS 3.x base score of 4.3. 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.0
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Mediawiki
Published: 2021-04-09
Last modified: 2026-06-17

Description

An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. ContentModelChange does not check if a user has correct permissions to create and set the content model of a nonexistent page.

Frequently asked questions

What is CVE-2021-30155?: An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. ContentModelChange does not check if a user has correct permissions to create and set the content model of a nonexistent page.
How severe is CVE-2021-30155?: CVE-2021-30155 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-30155 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30155?: CVE-2021-30155 primarily affects Mediawiki. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30155?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-30155 published?: CVE-2021-30155 was published on 2021-04-09 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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