CVE-2021-31556
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2....
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2. MWOAuthConsumerSubmitControl.php does not ensure that the length of an RSA key will fit in a MySQL blob.
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
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2. MWOAuthConsumerSubmitControl.php does not ensure that the length of an RSA key will fit in a MySQL blob.
- Record
CVE-2021-31556- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-1284
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2. MWOAuthConsumerSubmitControl.php does not ensure that the length of an RSA key will fit in a MySQL blob.
- Record
CVE-2021-31556- Updated
- 2026-11-02
EUVDEUVD-2021-18453 No score
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2. MWOAuthConsumerSubmitControl.php does not ensure that the length of an RSA key will fit in a MySQL blob.
- Record
EUVD-2021-18453- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-qm9m-9cq9-7p3v
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2....
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2. MWOAuthConsumerSubmitControl.php does not ensure that the length of an RSA key will fit in a MySQL blob.
- Record
GHSA-qm9m-9cq9-7p3v- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-327
- Updated
- 2026-11-02
OSV
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2. MWOAuthConsumerSubmitControl.php does not ensure that the length of an RSA key will fit in a MySQL blob.
- Record
CVE-2021-31556- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVBIT-mediawiki-2021-31556 No score
An issue was discovered in the Oauth extension for MediaWiki through 1.35.2. MWOAuthConsumerSubmitControl.php does not ensure that the length of an RSA key will fit in a MySQL blob.
- Record
BIT-mediawiki-2021-31556- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mediawikiBitnami |
before 1.35.3 | 1.35.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| 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-2021-31556 is a critical vulnerability (CVSS 9.8) in Mediawiki, published August 12, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.62%, the 76th percentile. Fixed in mediawiki 1.35.3.
References
phabricator.wikimedia.org/T277380
gerrit.wikimedia.org/r/q/I13ff0350a9a0a3cd5ab3e1f82dd0d8d9c13cf9e9
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QNEAI2T3Y65I55ZB6UE6RMC662RZTGRX
nvd.nist.gov/vuln/detail/CVE-2021-31556
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github.com/advisories/GHSA-qm9m-9cq9-7p3v