CVE-2026-27939: Statamic/cms Statamic Allows Authenticated Control Panel Vulnerability

HIGH
Advisory Identifier: GHSA-rw9x-pxqx-q789
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CVSS 8.8
CWE-287
Published
Advisory Summary

CVE-2026-27939 is a HIGH (CVSS 8.8) statamic allows authenticated control panel vulnerability (CWE-287: Improper Authentication) affecting Statamic/cms libraries in the Packagist ecosystem. The issue involves statamic allows authenticated control panel users to escalate privileges via elevated session bypass. Remediation is available by upgrading affected packages to version 6.4.0.

CVE-2026-27939 at a Glance

CVE Identifier CVE-2026-27939
GHSA Identifier GHSA-rw9x-pxqx-q789
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-287: Improper Authentication
Affected Product Statamic/cms
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-27939

To remediate this vulnerability, upgrade all affected Statamic/cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

statamic/cms fixed: 6.4.0 
Upgrade statamic/cms to 6.4.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for statamic/cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-27939, inspect your project dependencies for Statamic/cms:

inspect dependencies for statamic/cms

Analyze the terminal output to locate any version of Statamic/cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.4.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-287: Improper Authentication, where when an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. In Statamic/cms, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Impact Authenticated Control Panel users may under certain conditions obtain elevated privileges without completing the intended verification step. This can allow access to sensitive operations and, depending on the user’s existing permissions, may lead to privilege escalation. ## Patches This has been fixed in 6.4.0.

CVE-2026-27939 Affected Statamic/cms Versions

1 component(s)
Fixed Versions:
6.4.0
Product / Package Ecosystem Affected Versions Fixed Version
statamic/cms
 Packagist
≥ 6.0.0
< 6.4.0
6.4.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/statamic/cms/security/advisories/GHSA-rw9x-pxqx-q789
NVD — CVE-2026-27939 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27939
Security Fix Commit FIX COMMIT
https://github.com/statamic/cms/commit/8639ef96217eaa682bc42e8a62769cb7c6a85d3a
Statamic/cms Source Repository REPOSITORY
https://github.com/statamic/cms

Frequently Asked Questions

What is CVE-2026-27939?
CVE-2026-27939 is a security vulnerability in Statamic/cms involving Statamic allows Authenticated Control Panel users to escalate privileges via elevated session bypass under CWE-287: Improper Authentication.
Which Statamic/cms versions are affected?
Affected versions include releases prior to 6.4.0 across affected packages: statamic/cms.
What version fixes CVE-2026-27939?
Upgrading to 6.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is statamic/cms affected?
Yes, statamic/cms is affected in releases prior to 6.4.0. Upgrade your dependency to 6.4.0 or later.
What is the CVSS score of CVE-2026-27939?
CVE-2026-27939 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-27939?
CVE-2026-27939 is classified under CWE-287: Improper Authentication (When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.).
How can I check Packagist dependencies for CVE-2026-27939?
Run the dependency tree command: 'inspect dependencies for statamic/cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rw9x-pxqx-q789",
  "modified" : "2026-03-02T15:18:22Z",
  "published" : "2026-02-27T21:35:00Z",
  "aliases" : [ "CVE-2026-27939" ],
  "summary" : "Statamic allows Authenticated Control Panel users to escalate privileges via elevated session bypass",
  "details" : "## Impact\n\nAuthenticated Control Panel users may under certain conditions obtain elevated privileges without completing the intended verification step. This can allow access to sensitive operations and, depending on the user’s existing permissions, may lead to privilege escalation.\n\n## Patches\nThis has been fixed in 6.4.0.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "statamic/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.0.0"
      }, {
        "fixed" : "6.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/statamic/cms/security/advisories/GHSA-rw9x-pxqx-q789"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-27939"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/statamic/cms/commit/8639ef96217eaa682bc42e8a62769cb7c6a85d3a"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/statamic/cms"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-287" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-27T21:35:00Z",
    "nvd_published_at" : "2026-02-27T22:16:22Z"
  }
}