CVE-2026-123538 PUBLISHED

OpenAM before 16.1.4 SAML 1.x Signature Verification Issuer Impersonation

Assigner: VulnCheck
Reserved: 06.11.2026 Published: 08.11.2026 Updated: 08.11.2026

OpenAM before 16.1.4 does not verify that a signed SAML 1.x assertion or response was signed by the partner named as its issuer, accepting a signature from any certificate in OpenAM's keystore. An attacker holding such a private key, such as a trusted SAML 1.x partner, can forge assertions claiming another partner's issuer and sign in as that partner's users, including privileged ones.

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 7.5

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	High
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 6.6

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	High	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	OpenIdentityPlatform
Product	OpenAM
Versions	Default: unaffected affected from 0 to 16.1.4 (excl.) Version 16.1.4 is unaffected

CVE-2026-123538 PUBLISHED

OpenAM before 16.1.4 SAML 1.x Signature Verification Issuer Impersonation

Metrics

Product Status

Credits

References

Problem Types