How severe is CVE-2021-30158?

CVE-2021-30158 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-30158 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30158?

CVE-2021-30158 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-2021-30158?

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

When was CVE-2021-30158 published?

CVE-2021-30158 was published on 2021-04-06 and last updated on 2026-06-17.

CVE-2021-30158

CVE-2021-30158 is a medium-severity vulnerability in Mediawiki with a CVSS 3.x base score of 5.3. 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-287.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Mediawiki
Published: 2021-04-06
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. Blocked users are unable to use Special:ResetTokens. This has security relevance because a blocked user might have accidentally shared a token, or might know that a token has been compromised, and yet is not able to block any potential future use of the token by an unauthorized party.

Frequently asked questions

What is CVE-2021-30158?: An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. Blocked users are unable to use Special:ResetTokens. This has security relevance because a blocked user might have accidentally shared a token, or might know that a token has been compromised, and yet is not able to block any potential future use of the token by an unauthorized party.
How severe is CVE-2021-30158?: CVE-2021-30158 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-30158 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30158?: CVE-2021-30158 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-2021-30158?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-30158 published?: CVE-2021-30158 was published on 2021-04-06 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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