How severe is CVE-2021-31548?

CVE-2021-31548 has a CVSS 3.x base score of 6.5, 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 high, and availability none.

Is CVE-2021-31548 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31548?

CVE-2021-31548 affects Mediawiki. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-31548?

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

When was CVE-2021-31548 published?

CVE-2021-31548 was published on 2021-04-22 and last updated on 2026-06-17.

CVE-2021-31548

CVE-2021-31548 is a medium-severity vulnerability in Mediawiki with a CVSS 3.x base score of 6.5. 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Mediawiki
Published: 2021-04-22
Last modified: 2026-06-17

Description

An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. A MediaWiki user who is partially blocked or was unsuccessfully blocked could bypass AbuseFilter and have their edits completed.

Frequently asked questions

What is CVE-2021-31548?: An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. A MediaWiki user who is partially blocked or was unsuccessfully blocked could bypass AbuseFilter and have their edits completed.
How severe is CVE-2021-31548?: CVE-2021-31548 has a CVSS 3.x base score of 6.5, 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 high, and availability none.
Is CVE-2021-31548 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31548?: CVE-2021-31548 affects Mediawiki. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-31548?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-31548 published?: CVE-2021-31548 was published on 2021-04-22 and last updated on 2026-06-17.

References

Affected products (1)

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

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