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CRITICAL severity

CVE-2026-9093

CRITICAL

CVE-2026-9093 is a critical-severity (CVSS 9.8) vulnerability in github.com/casdoor/casdoor. O3 Security confirms whether CVE-2026-9093 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Casdoor does not validate the AudienceRestriction element in SAML assertions

Also known asGO-2026-5894
Published
May 28, 2026
Updated
Jul 7, 2026
Affected
1 pkg
Patched
None yet
Exploits
None indexed
Exploitation data as of Aug 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-9093.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs29th percentile — riskier than 29% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2026-9093 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 363,908 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐹github.com/casdoor/casdoor

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

In Casdoor versions 2.362.0 and earlier, the SAML service provider implementation does not validate the AudienceRestriction element in SAML assertions. The buildSp function in object/saml_sp.go never sets AudienceURI on the gosaml2 SAMLServiceProvider struct and never inspects WarningInfo.NotInAudience. This allows assertions issued for other service providers to be accepted by Casdoor.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/casdoor/casdoorall versionsNo fix

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/casdoor/casdoor. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Remediation status

    No patched version of github.com/casdoor/casdoor has shipped for CVE-2026-9093 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether CVE-2026-9093 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-9093. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In Casdoor versions 2.362.0 and earlier, the SAML service provider implementation does not validate the AudienceRestriction element in SAML assertions. The buildSp function in object/saml_sp.go never sets AudienceURI on the gosaml2 SAMLServiceProvider struct and never inspects WarningInfo.NotInAudience. This allows assertions issued for other service providers to be accepted by Casdoor.
O3 Security · Impact-Aware SCA

Is CVE-2026-9093 in your dependencies?

O3 detects CVE-2026-9093 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

CVE-2026-9093: casdoor (Critical 9.8) | O3 Security