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...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-44857- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 4.0 Medium
AV:N/AC:L/Au:S/C:N/I:P/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-44857- Updated
- 2026-11-02
EUVDEUVD-2021-31660 No score
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.
- Record
EUVD-2021-31660- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-x4wg-g4fv-f8m6
An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37...
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.
- Record
GHSA-x4wg-g4fv-f8m6- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-269, CWE-862
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-44857- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVDEBIAN-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.
- Record
DEBIAN-CVE-2021-44857- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVUBUNTU-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.
- Record
UBUNTU-CVE-2021-44857- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVBIT-mediawiki-2021-44857 No score
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.
- Record
BIT-mediawiki-2021-44857- Updated
- 2026-11-02
OSVMGASA-2021-0568 No score
Updated mediawiki packages fix security vulnerabilities
Updated mediawiki packages fix security vulnerabilities:
== Security fixes ==
- (T292763. CVE-2021-44854) REST API incorrectly publicly caches autocomplete search results from private wikis.
- (T271037, CVE-2021-44856) Title blocked in AbuseFilter can be created via Special:ChangeContentModel.
- (T297322, CVE-2021-44857) Unauthorized users can use action=mcrundo to replace the content of arbitrary pages.
- (T297322, CVE-2021-44858) Unauthorized users can view contents of private wikis using various actions.
- (T297574, CVE-2021-45038) Unauthorized users can access private wiki contents using rollback action
=== Extension security fixes ===
- (T293589, CVE-2021-44855) Blind Stored XSS in VisualEditor media dialog.
- (T294686) Special:Nuke doesn't actually delete pages.
- Record
MGASA-2021-0568- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mediawikiBitnami |
before 1.35.5, 1.36.0 up to 1.36.3, 1.37.0 up to 1.37.1 | 1.35.51.36.31.37.1 |
mediawikiDebian:12 |
before 1:1.35.5-1 | 1:1.35.5-1 |
mediawikiDebian:13 |
before 1:1.35.5-1 | 1:1.35.5-1 |
mediawikiDebian:14 |
before 1:1.35.5-1 | 1:1.35.5-1 |
mediawikiDebian:11 From an advisory covering 3 CVEs |
before 1:1.35.4-1+deb11u2, plus listed versions 1:1.35.2-11:1.35.3-11:1.35.4-11:1.35.4-1~deb11u1 |
1:1.35.4-1+deb11u2 |
mediawikiMageia:8 From an advisory covering 6 CVEs |
before 1.35.5-1.mga8 | 1.35.5-1.mga8 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-44857 is a medium vulnerability (CVSS 6.5) in Mediawiki, published December 15, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.90%, the 59th percentile. Fixed in mediawiki 1.35.5.
References
phabricator.wikimedia.org/T297322
mediawiki.org/wiki/2021-12_security_release/FAQ
security.gentoo.org/glsa/202305-24
nvd.nist.gov/vuln/detail/CVE-2021-44857
github.com/advisories/GHSA-x4wg-g4fv-f8m6
security-tracker.debian.org/tracker/CVE-2021-44857
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advisories.mageia.org/MGASA-2021-0568.html
bugs.mageia.org/show_bug.cgi?id=29772
lists.wikimedia.org/hyperkitty/list/[email protected]/thread/QEN3EK4JXAVJMJ5GF3GYOAKNJPEKFQYA
ubuntu.com/security/CVE-2021-44857
cve.org/CVERecord?id=CVE-2021-44857