CVE-2026-33541
TSPortal's Uncontrolled User Creation via Validation Side Effects Leads to Potential Denial of Service
CVE-2026-33541 is a medium vulnerability (CVSS 6.5) in Miraheze Tsportal, published March 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 24th percentile. Fixed in miraheze/ts-portal 34.
- Severity
- 6.5 MediumCVSS 3.1, CVE List
- Exploit chance
- 0.31%EPSS, 24th percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
34miraheze/ts-portal +1 more
Description
TSPortal is the WikiTide Foundation’s in-house platform used by the Trust and Safety team to manage reports, investigations, appeals, and transparency work. Prior to version 34, a flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS). Version 34 contains a fix for the issue.
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
- None
- Availability
- High
Exploit likelihood
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
miraheze/ts-portalPackagist | through 33 | 34 |
miraheze/ts-portalPackagist | before 34, plus listed versions v1v10v11v12v13 Show 28 moreShow lessv14v15v16v17v18v19v2v20v21v22v23v24v25v26v27v28v29v3v30v31v32v33v4v5v6v7v8v9 | 34 |
What each source reports
CVE List Score used 6.5
TSPortal's Uncontrolled User Creation via Validation Side Effects Leads to Potential Denial of Service
TSPortal is the WikiTide Foundation’s in-house platform used by the Trust and Safety team to manage reports, investigations, appeals, and transparency work. Prior to version 34, a flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS). Version 34 contains a fix for the issue.
- Record
CVE-2026-33541- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2026-16398 6.5
TSPortal is the WikiTide Foundation’s in-house platform used by the Trust and Safety team to manage reports, investigations, appeals, and transparency work. Prior to version 34, a flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS). Version 34 contains a fix for the issue.
- Record
EUVD-2026-16398- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-f346-8rp3-4h9h 6.5
TSPortal's Uncontrolled User Creation via Validation Side Effects Leads to Potential Denial of Service
Summary
A flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS).
Details
When submitting a Data Processing Agreement (DPA) request in TSPortal, the DPAAlreadyLive validation rule previously called User::findOrCreate().
This method created a user record if one did not already exist.
Although username validation (via MirahezeUsernameRule) correctly rejected invalid usernames, the DPAAlreadyLive rule was still executed during validation. Because it performed a state-changing operation, it created user records even when the overall validation failed and no DPA was created.
As a result:
- Validation correctly rejected invalid input
- However, user records were still inserted into the database as a side effect
These records were created:
- Without a successful DPA request
- Without audit logging tied to a completed action
- Without visibility into their origin
Impact
An attacker could exploit this behavior by automating requests with invalid usernames, resulting in:
- Mass creation of arbitrary user records
- Unbounded database growth
- Increased storage and indexing overhead
- Potential degradation of application performance
At scale, this could lead to a denial of service condition due to resource exhaustion.
Proof of Concept
- Submit a DPA request using an invalid username
- Ensure the request fails validation due to
MirahezeUsernameRule - Observe that a corresponding user record is still created in the database
This behavior was confirmed prior to remediation.
Root Cause
The issue stemmed from:
- Performing state-changing operations (
findOrCreate) inside validation logic - Validation rules executing regardless of overall validation success
- Lack of separation between validation and persistence layers
Mitigation
The issue has been fixed by removing database write operations from validation logic.
Specifically:
- Replaced
User::findOrCreate()with a non-mutating lookup (User::firstWhere(...)) - Ensured validation rules only perform read operations
- Prevented user creation unless all validation passes
- Record
GHSA-f346-8rp3-4h9h- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
NVD 6.5
TSPortal is the WikiTide Foundation’s in-house platform used by the Trust and Safety team to manage reports, investigations, appeals, and transparency work. Prior to version 34, a flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS). Version 34 contains a fix for the issue.
- Record
CVE-2026-33541- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
OSV 6.5
TSPortal's Uncontrolled User Creation via Validation Side Effects Leads to Potential Denial of Service
TSPortal is the WikiTide Foundation’s in-house platform used by the Trust and Safety team to manage reports, investigations, appeals, and transparency work. Prior to version 34, a flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS). Version 34 contains a fix for the issue.
- Record
CVE-2026-33541- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
OSVGHSA-f346-8rp3-4h9h 6.5
TSPortal's Uncontrolled User Creation via Validation Side Effects Leads to Potential Denial of Service
Summary
A flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS).
Details
When submitting a Data Processing Agreement (DPA) request in TSPortal, the DPAAlreadyLive validation rule previously called User::findOrCreate().
This method created a user record if one did not already exist.
Although username validation (via MirahezeUsernameRule) correctly rejected invalid usernames, the DPAAlreadyLive rule was still executed during validation. Because it performed a state-changing operation, it created user records even when the overall validation failed and no DPA was created.
As a result:
- Validation correctly rejected invalid input
- However, user records were still inserted into the database as a side effect
These records were created:
- Without a successful DPA request
- Without audit logging tied to a completed action
- Without visibility into their origin
Impact
An attacker could exploit this behavior by automating requests with invalid usernames, resulting in:
- Mass creation of arbitrary user records
- Unbounded database growth
- Increased storage and indexing overhead
- Potential degradation of application performance
At scale, this could lead to a denial of service condition due to resource exhaustion.
Proof of Concept
- Submit a DPA request using an invalid username
- Ensure the request fails validation due to
MirahezeUsernameRule - Observe that a corresponding user record is still created in the database
This behavior was confirmed prior to remediation.
Root Cause
The issue stemmed from:
- Performing state-changing operations (
findOrCreate) inside validation logic - Validation rules executing regardless of overall validation success
- Lack of separation between validation and persistence layers
Mitigation
The issue has been fixed by removing database write operations from validation logic.
Specifically:
- Replaced
User::findOrCreate()with a non-mutating lookup (User::firstWhere(...)) - Ensured validation rules only perform read operations
- Prevented user creation unless all validation passes
- Record
GHSA-f346-8rp3-4h9h- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.