CVE-2026-9090: Github.com/casdoor/casdoor Authentication Bypass Vulnerability

CRITICAL
Advisory Identifier: GHSA-fwgq-j9r9-qjgr
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CVSS 9.1
CWE-287
Published
Advisory Summary

CVE-2026-9090 is a CRITICAL (CVSS 9.1) authentication bypass vulnerability (CWE-287: Improper Authentication) affecting Github.com/casdoor/casdoor libraries in the Go ecosystem. The issue involves casdoor has an authentication bypass. Remediation is available in the latest vendor maintenance releases.

CVE-2026-9090 at a Glance

CVE Identifier CVE-2026-9090
GHSA Identifier GHSA-fwgq-j9r9-qjgr
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-287: Improper Authentication
Affected Product Github.com/casdoor/casdoor
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 9.1

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

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

How to Fix CVE-2026-9090

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

github.com/casdoor/casdoor fixed: Latest secure release 
Upgrade github.com/casdoor/casdoor to Latest secure release
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 github.com/casdoor/casdoor

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-9090, inspect your project dependencies for Github.com/casdoor/casdoor:

inspect dependencies for github.com/casdoor/casdoor

Analyze the terminal output to locate any version of Github.com/casdoor/casdoor in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), 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 Github.com/casdoor/casdoor, 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

Casdoor versions 2.362.0 and earlier contain a vulnerability that allows an attacker to bypass authentication by supplying an arbitrary signing certificate. The buildSpCertificateStore function extracts the X.509 certificate directly from the incoming SAMLResponse instead of using the trusted pre-configured Identity Provider certificate, allowing an attacker to forge assertions signed with an attacker-controlled key.

CVE-2026-9090 Affected Github.com/casdoor/casdoor Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/casdoor/casdoor
golang/github.com/casdoor/casdoor
Go
≤ 1.1000.1-0.20260321120606-239e8bd69487

References

NVD — CVE-2026-9090 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-9090
Github.com/casdoor/casdoor Source Repository REPOSITORY
https://github.com/casdoor/casdoor
kb.cert.org/vuls/id/780781 WEB
https://kb.cert.org/vuls/id/780781

Frequently Asked Questions

What is CVE-2026-9090?
CVE-2026-9090 is a security vulnerability in Github.com/casdoor/casdoor involving Casdoor has an authentication bypass under CWE-287: Improper Authentication.
Which Github.com/casdoor/casdoor versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/casdoor/casdoor.
What version fixes CVE-2026-9090?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/casdoor/casdoor affected?
Yes, github.com/casdoor/casdoor is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-9090?
CVE-2026-9090 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-9090?
CVE-2026-9090 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 Go dependencies for CVE-2026-9090?
Run the dependency tree command: 'inspect dependencies for github.com/casdoor/casdoor'. 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-fwgq-j9r9-qjgr",
  "modified" : "2026-07-02T18:36:50Z",
  "published" : "2026-05-28T18:30:32Z",
  "aliases" : [ "CVE-2026-9090" ],
  "summary" : "Casdoor has an authentication bypass",
  "details" : "Casdoor versions 2.362.0 and earlier contain a vulnerability that allows an attacker to bypass authentication by supplying an arbitrary signing certificate. The buildSpCertificateStore function extracts the X.509 certificate directly from the incoming SAMLResponse instead of using the trusted pre-configured Identity Provider certificate, allowing an attacker to forge assertions signed with an attacker-controlled key.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/casdoor/casdoor"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.1000.1-0.20260321120606-239e8bd69487"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-9090"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/casdoor/casdoor"
  }, {
    "type" : "WEB",
    "url" : "https://kb.cert.org/vuls/id/780781"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-287" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-02T18:36:50Z",
    "nvd_published_at" : "2026-05-28T17:16:33Z"
  }
}