CVE-2026-27886: Strapi may leak sensitive data via relational filtering due to lack of query sanitization

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 2.5%, percentile 85: FIRST’s model estimates a 2.5% chance of exploitation activity in the next 30 days, higher than 85% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes @strapi/strapi (npm) >= 4.0.0, < 5.37.0, fixed in 5.37.0. Check your lockfile, including transitive dependencies.

What it is

Strapi is an open source headless content management system. Strapi versions starting in 4.0.0 and 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 adminusers 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 adminusers 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 in version 5.37.0 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.

From the GitHub advisory

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 =5.37.0

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 adminusers 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 adminusers 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.

Weakness type: CWE-22, CWE-200, CWE-943.

Product: @strapi/strapi (npm) · Assigned by: GitHub_M · Published: 2026-05-14

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 2.52% probability of exploitation activity in the next 30 days; percentile 85.

Timeline

• 2026-05-14 — CVE record last updated
• 2026-05-14 — CVE record published by GitHub_M
• 2026-05-14 — GitHub-reviewed advisory GHSA-rjg2-95x7-8qmx published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-rjg2-95x7-8qmx github.com
2. CVE.org record CVE-2026-27886 cve.org
3. NVD entry CVE-2026-27886 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com

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