Mediawiki - CentralAuth Extension: Improper Removal of Sensitive Information Before Storage or Transfer
CVE-2026-39937 is a high-severity improper removal of sensitive information before storage or transfer vulnerability in Mediawiki - CentralAuth Extension from Wikimedia Foundation, with a CVSS 4.0 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 1.43 as the first without the flaw, so updating Mediawiki - CentralAuth Extension to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Mediawiki - CentralAuth Extension to 1.43 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| The Wikimedia Foundation | Mediawiki - CentralAuth Extension | before 1.43 | 1.43 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- LowLimited loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- LowLimited loss of availability on the vulnerable system.
- Confidentiality (other systems)
- LowLimited loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- LowLimited loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- LowLimited loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA.
Official description
Improper removal of sensitive information before storage or transfer vulnerability in The Wikimedia Foundation Mediawiki - CentralAuth Extension allows Resource Leak Exposure. The issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Removal of Sensitive Information Before Storage or Transfer
The product stores, transfers, or shares a resource that contains sensitive information, but it does not properly remove that information before the product makes the resource available to unauthorized actors.
How developers prevent this class of flaw
- Clearly specify which information should be regarded as private or sensitive, and require that the product offers functionality that allows the user to cleanse the sensitive information from the resource before it is published or exported to other parties.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
- Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
More Improper Removal of Sensitive Information Before Storage or Transfer vulnerabilities (CWE-212)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Mediawiki - CentralAuth Extension
- 7.2 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Removal of Sensitive Information Before Storage or Transfer vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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