---
title: "CVE-2026-9090: Casdoor has an authentication bypass"
url: https://erroneo.us/security/cve/CVE-2026-9090/
description: "CVE-2026-9090 (github.com/casdoor/casdoor (Go)): Casdoor versions 2.362.0 and earlier contain a vulnerability that allows an attacker to bypass…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-28
date_modified: 2026-07-02
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-9090"
kev: false
cvss: 9.1
epss: 0.00201
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-9090: Casdoor has an authentication bypass

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- 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 0.2% , percentile 9: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 9% of all scored CVEs (low). 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 github.com/casdoor/casdoor (Go) <= 1.1000.1-0.20260321120606-239e8bd69487, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- Go `github.com/casdoor/casdoor` <= 1.1000.1-0.20260321120606-239e8bd69487 → fixed: none listed

## Affected products (CVE record)

- Casdoor Casdoor: <= 2.362.0

## Severity

- CISA-ADP CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.20% probability of exploitation activity in the next 30 days; percentile 9.

## Sources

- [GitHub Advisory GHSA-fwgq-j9r9-qjgr](https://github.com/advisories/GHSA-fwgq-j9r9-qjgr)
- [CVE.org record CVE-2026-9090](https://www.cve.org/CVERecord?id=CVE-2026-9090)
- [NVD entry CVE-2026-9090](https://nvd.nist.gov/vuln/detail/CVE-2026-9090)
- [kb.cert.org](https://kb.cert.org/vuls/id/780781)

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Source page: https://erroneo.us/security/cve/CVE-2026-9090/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt