How severe is CVE-2021-44857?

CVE-2021-44857 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-2021-44857 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-44857?

CVE-2021-44857 affects Mediawiki. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-44857?

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

When was CVE-2021-44857 published?

CVE-2021-44857 was published on 2021-12-17 and last updated on 2026-06-17.

CVE-2021-44857

CVE-2021-44857 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Mediawiki
Published: 2021-12-17
Last modified: 2026-06-17

Description

An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. It is possible to use action=mcrundo followed by action=mcrrestore to replace the content of any arbitrary page (that the user doesn't have edit rights for). This applies to any public wiki, or a private wiki that has at least one page set in $wgWhitelistRead.

Frequently asked questions

What is CVE-2021-44857?: An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. It is possible to use action=mcrundo followed by action=mcrrestore to replace the content of any arbitrary page (that the user doesn't have edit rights for). This applies to any public wiki, or a private wiki that has at least one page set in $wgWhitelistRead.
How severe is CVE-2021-44857?: CVE-2021-44857 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-2021-44857 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-44857?: CVE-2021-44857 affects Mediawiki. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-44857?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-44857 published?: CVE-2021-44857 was published on 2021-12-17 and last updated on 2026-06-17.

References

Affected products (1)

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

More vulnerabilities in Mediawiki

CVE-2025-67484 — Critical (CVSS 9.8): Vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files…
CVE-2024-34502 — Critical (CVSS 9.8): An issue was discovered in WikibaseLexeme in MediaWiki before 1.39.6, 1.40.x before 1.40.2, and 1.41.x before 1.41.1.…
CVE-2023-37303 — Critical (CVSS 9.8): An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. In certain situations, an attempt to…
CVE-2023-29141 — Critical (CVSS 9.8): An issue was discovered in MediaWiki before 1.35.10, 1.36.x through 1.38.x before 1.38.6, and 1.39.x before 1.39.3. An…
CVE-2022-29906 — Critical (CVSS 9.8): The admin API module in the QuizGame extension for MediaWiki through 1.37.2 (before…
CVE-2022-29904 — Critical (CVSS 9.8): The SemanticDrilldown extension for MediaWiki through 1.37.2 (before e688bdba6434591b5dff689a45e4d53459954773) allows…

All CVEs affecting Mediawiki →

Other CWE-862 (Missing Authorization) vulnerabilities

CVE-2026-0092 — Critical (CVSS 10.0): In Package Manager, there is a possible device lock controller bypass due to a missing permission check. This could…
CVE-2026-33712 — Critical (CVSS 10.0): Typebot is a chatbot builder tool. In versions 3.15.2 and prior, the preview chat endpoint (POST…
CVE-2026-2031 — Critical (CVSS 10.0): An Improper Access Control vulnerability in several internal API endpoints for Google Cloud Application Integration…
CVE-2026-34976 — Critical (CVSS 10.0): Dgraph is an open source distributed GraphQL database. Prior to 25.3.1, the restoreTenant admin mutation is missing…
CVE-2025-30416 — Critical (CVSS 10.0): Sensitive data disclosure and manipulation due to missing authorization. The following products are affected: Acronis…
CVE-2025-45854 — Critical (CVSS 10.0): /server/executeExec of JEHC-BPM 2.0.1 allows attackers to execute arbitrary code via execParams.

Browse all CWE-862 (Missing Authorization) vulnerabilities →