CVE-2026-9098: Github.com/casdoor/casdoor Casdoor SAML Callback Handler Accepts Vulnerability

CRITICAL
Advisory Identifier: GHSA-mfvp-7p3v-x9mh
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CVSS 9.1
CWE-488
Published
Advisory Summary

CVE-2026-9098 is a CRITICAL (CVSS 9.1) casdoor saml callback handler accepts vulnerability (CWE-488: Exposure of Data Element to Wrong Session) affecting Github.com/casdoor/casdoor libraries in the Go ecosystem. The issue involves casdoor saml callback handler accepts any well-formed samlresponse sent to /api/acs without verifying that it corresponds to an authnrequest. Remediation is available in the latest vendor maintenance releases.

CVE-2026-9098 at a Glance

CVE Identifier CVE-2026-9098
GHSA Identifier GHSA-mfvp-7p3v-x9mh
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-488: Exposure of Data Element to Wrong Session
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-2026-9098

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-2026-9098, 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-488: Exposure of Data Element to Wrong Session, where the product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session. 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

In Casdoor versions 2.362.0 and earlier, the SAML callback handler in controllers/auth.go accepts any well-formed SAMLResponse sent to /api/acs without verifying that it corresponds to an AuthnRequest previously issued by Casdoor. Additionally, if an administrator disables or deletes an IdP (Identity Provider) after a SAML flow has started, the handler still processes the response using the provider snapshot loaded at the start of the request. As a result, an attacker controlling a registered upstream IdP can send unsolicited SAML responses, or replay a legitimately captured response in a different session or after the original flow has ended. In both cases, Casdoor accepts the response and issues a session, enabling persistent unauthorized access.

CVE-2026-9098 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-2026-9098 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-9098
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-2026-9098?
CVE-2026-9098 is a security vulnerability in Github.com/casdoor/casdoor involving Casdoor SAML callback handler accepts any well-formed SAMLResponse sent to /api/acs without verifying that it corresponds to an AuthnRequest under CWE-488: Exposure of Data Element to Wrong Session.
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-2026-9098?
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-2026-9098?
CVE-2026-9098 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-2026-9098?
CVE-2026-9098 is classified under CWE-488: Exposure of Data Element to Wrong Session (The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.).
How can I check Go dependencies for CVE-2026-9098?
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-mfvp-7p3v-x9mh",
  "modified" : "2026-07-02T18:37:59Z",
  "published" : "2026-05-28T18:30:32Z",
  "aliases" : [ "CVE-2026-9098" ],
  "summary" : "Casdoor SAML callback handler accepts any well-formed SAMLResponse sent to /api/acs without verifying that it corresponds to an AuthnRequest",
  "details" : "In Casdoor versions 2.362.0 and earlier, the SAML callback handler in controllers/auth.go accepts any well-formed SAMLResponse sent to /api/acs without verifying that it corresponds to an AuthnRequest previously issued by Casdoor. Additionally, if an administrator disables or deletes an IdP (Identity Provider) after a SAML flow has started, the handler still processes the response using the provider snapshot loaded at the start of the request. As a result, an attacker controlling a registered upstream IdP can send unsolicited SAML responses, or replay a legitimately captured response in a different session or after the original flow has ended. In both cases, Casdoor accepts the response and issues a session, enabling persistent unauthorized access.",
  "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-2026-9098"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/casdoor/casdoor"
  }, {
    "type" : "WEB",
    "url" : "https://kb.cert.org/vuls/id/780781"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-488" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-02T18:37:59Z",
    "nvd_published_at" : "2026-05-28T17:16:34Z"
  }
}