Summary
Strapi may leak sensitive data via relational filtering due to lack of query sanitization
Summary of CVE-2026-27886 Vulnerability Details
- CVE: CVE-2026-27886
- CVSS v3.1 Vector:
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N(9.3, Critical) - Affected Versions:
@strapi/strapi<=5.36.1 - How to Patch: Immediately update your Strapi to >=5.37.0
Description of CVE-2026-27886
Strapi versions prior to 5.37.0 did not sufficiently sanitize query parameters when filtering content via relational fields. An unauthenticated attacker could use the where query parameter on any publicly-accessible content-type with an updatedBy (or other admin-relation) field to perform a boolean-oracle attack against private fields on the joined admin_users table, including the resetPasswordToken field. Extracting an admin reset token via this oracle made full administrative account takeover possible without authentication.
When a filter such as where[updatedBy][resetPasswordToken][$startsWith]=a was applied to a public Content API endpoint, the underlying query generation performed a LEFT JOIN against the admin_users table and emitted a WHERE clause referencing the joined column. The query parameter sanitization layer did not block operator chains that traversed into relational target schemas the caller had no read permission on, allowing the response count to be used as a one-bit oracle on any admin-table field.
The patch introduces explicit query-parameter sanitization at the controller and service boundary via three new primitives: strictParam, addQueryParams, and addBodyParams. Operator chains that traverse into restricted relational targets are now rejected before reaching the database.
IoC's for CVE-2026-27886
Indicators that an instance running an unpatched version may have been exploited:
- Server access logs containing query strings traversing into admin-relation private fields. Regex:
\?(.*&)?where\[(updatedBy|createdBy|publishedBy)\]\[(email|password|resetPasswordToken|confirmationToken|firstname|lastname|preferedLanguage)\]\[\$(startsWith|contains|eq|gt|lt|ge|le|in|notIn|notNull|null)\]= - High volume of public Content API requests from a single IP iterating through a hex alphabet (
0-9,a-f) on the same content-type endpoint with progressively-longer filter values - Subsequent
POST /admin/reset-passwordcalls using a reset token that the legitimate admin did not request - Successful admin password change immediately following a burst of public Content API requests with
where[updatedBy]query parameters - Sustained burst of identical-shape requests with only the trailing character of the filter value varying
Credit
Discovered by: James Doll - WildWest CyberSecurity
Contact: [email protected]
Website: https://wildwestcyber.com
LinkedIn: https://www.linkedin.com/in/james-doll-273a61243
Impact
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-27886? CVE-2026-27886 is a critical-severity path traversal vulnerability in @strapi/strapi (npm), affecting versions >= 4.0.0, < 5.37.0. It is fixed in 5.37.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- Which versions of @strapi/strapi are affected by CVE-2026-27886? @strapi/strapi (npm) versions >= 4.0.0, < 5.37.0 is affected.
- Is there a fix for CVE-2026-27886? Yes. CVE-2026-27886 is fixed in 5.37.0. Upgrade to this version or later.
- Is CVE-2026-27886 exploitable, and should I be worried? Whether CVE-2026-27886 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-27886 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-27886? Upgrade
@strapi/strapito 5.37.0 or later.