CVE-2021-44856
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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- 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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
CVE-2021-44856- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-754
- Updated
- 2026-11-02
CVE List
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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
CVE-2021-44856- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-754
- Updated
- 2026-11-02
EUVDEUVD-2021-31659
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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
EUVD-2021-31659- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gmch-57w2-pj7q
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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
GHSA-gmch-57w2-pj7q- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-754
- 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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
CVE-2021-44856- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-44856
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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
DEBIAN-CVE-2021-44856- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-44856
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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
UBUNTU-CVE-2021-44856- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
OSVBIT-mediawiki-2021-44856 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. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
- Record
BIT-mediawiki-2021-44856- 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:10 From an advisory covering 6 CVEs |
before 1:1.31.16-1+deb10u3, plus listed versions 1:1.31.10-1~deb10u11:1.31.12-1~deb10u11:1.31.14-1~deb10u11:1.31.16-1+deb10u21:1.31.16-1~deb10u1 Show 11 moreShow less1:1.31.2-11:1.31.4-11:1.31.4-1~deb10u11:1.31.5-11:1.31.5-21:1.31.5-31:1.31.6-11:1.31.6-1~deb10u11:1.31.7-11:1.31.7-1~deb10u11:1.31.8-1 |
1:1.31.16-1+deb10u3 |
mediawikiDebian:11 From an advisory covering 15 CVEs |
before 1:1.35.8-1~deb11u1, plus listed versions 1:1.35.2-11:1.35.3-11:1.35.4-11:1.35.4-1+deb11u21:1.35.4-1~deb11u1 Show 4 moreShow less1:1.35.5-11:1.35.5-21:1.35.6-11:1.35.7-1 |
1:1.35.8-1~deb11u1 |
mediawikiMageia:8 From an advisory covering 6 CVEs |
before 1.35.5-1.mga8 | 1.35.5-1.mga8 |
mediawikiUbuntu:18.04:LTS |
All versions, plus listed versions 1:1.27.3-11:1.27.4-11:1.27.4-21:1.27.4-3 |
None known |
mediawikiUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 1:1.31.2-1ubuntu11:1.31.5-11:1.31.5-1ubuntu11:1.31.5-21:1.31.5-3 Show 4 moreShow less1:1.31.5-3ubuntu11:1.31.6-11:1.31.7-11:1.31.7-1ubuntu0.1~esm1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-44856 is a medium vulnerability (CVSS 5.3) in Mediawiki, published December 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.53%, the 44th percentile. Fixed in mediawiki 1.35.5.
References
phabricator.wikimedia.org/T271037
security.gentoo.org/glsa/202305-24
nvd.nist.gov/vuln/detail/CVE-2021-44856
github.com/advisories/GHSA-gmch-57w2-pj7q
security-tracker.debian.org/tracker/CVE-2021-44856
advisories.mageia.org/MGASA-2021-0568.html