What is CVE-2026-123540?

CVE-2026-123540 is a low-severity vulnerability in Openidentityplatform Openam, classified under Improper Encoding or Escaping of Output. CVSS score: 2.0/10. Published 2026-11-08.

How severe is CVE-2026-123540?

Low severity. CVSS v3 base score is 2.0 out of 10.

Vulnerability in Openidentityplatform Openam

CVE-2026-123540

OpenAM before 16.1.4 contains an incomplete output encoding vulnerability that allows a SAML 1.x identity provider to alter attribute values by injecting unencoded content into the service provider auto-submitted form. Attackers controlling a trusted identity provider can craft assertion attribute names or values that reach the target application in modified form, undermining the integrity of received attributes.

Published 2026-11-08.

CVSS v3 metric

CVSS v3 base score 2.0 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Openidentityplatform Openam

Weakness classification (CWE)

CWE-116 — Improper Encoding or Escaping of Output

References

GitHub Security Advisory (GHSA-pw99-8h4m-p3gm) (vendor-advisory)
VulnCheck Advisory: OpenAM before 16.1.4 Incomplete Attribute Encoding in SAML 1.x Form POST (third-party-advisory)

Frequently asked questions

What is CVE-2026-123540?: CVE-2026-123540 is a low-severity vulnerability in Openidentityplatform Openam, classified under Improper Encoding or Escaping of Output. CVSS score: 2.0/10. Published 2026-11-08.
How severe is CVE-2026-123540?: Low severity. CVSS v3 base score is 2.0 out of 10.