What is CVE-2026-9090?

CVE-2026-9090 is a critical-severity vulnerability in Casdoor, classified under CWE-347 IMPROPER VERIFICATION OF CRYPTOGRAPHIC SIGNATURE. CVSS score: 9.1/10. Published 2026-05-28.

How severe is CVE-2026-9090?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Is CVE-2026-9090 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Casdoor

CVE-2026-9090

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.

EPSS: 0.002 (11.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Casdoor — versions 0

Public proof-of-concept exploits

References

cret@cert.org

Frequently asked questions

What is CVE-2026-9090?: CVE-2026-9090 is a critical-severity vulnerability in Casdoor, classified under CWE-347 IMPROPER VERIFICATION OF CRYPTOGRAPHIC SIGNATURE. CVSS score: 9.1/10. Published 2026-05-28.
How severe is CVE-2026-9090?: Critical severity. CVSS v3 base score is 9.1 out of 10.
Is CVE-2026-9090 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.