CVE-2026-123543: DoS (CVSS 7.5)

Description

OpenAM before 16.1.4 contains a denial of service vulnerability that allows unauthenticated attackers to exhaust server resources by sending serialized Java data without size or structure limits. Attackers can send small crafted requests to remote SDK endpoints, classic login pages, or the administration console to block authentication, session validation and policy decisions.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.34%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

References

Other References

https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-x7wr-5gxg-v833 https://www.vulncheck.com/advisories/openam-before-16.1.4-unauthenticated-dos-via-unbounded-java-deserialisation

Frequently Asked Questions

What is CVE-2026-123543? +

OpenAM before 16.1.4 contains a denial of service vulnerability that allows unauthenticated attackers to exhaust server resources by sending serialized Java data without size or structure limits. Attackers can send small crafted requests to remote SDK endpoints, classic login pages, or the administration console to block authentication, session validation and policy decisions. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-123543? +

CVE-2026-123543 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-123543? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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