CVE-2026-21834 (CVSS 3.1)

Description

HCL AION is affected by a vulnerability where the Content-Security-Policy (CSP) security response header was missing from application responses. Without this header, the browser does not restrict the sources of scripts and other content, increasing exposure to cross-site scripting and content-injection attacks, potentially resulting in unintended behavior or security impact under certain conditions.

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CVSS v3.1 Score

3.1

LOW

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

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.04%

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-1021 CWE-1021

References

Other References

https://support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0135217

Frequently Asked Questions

What is CVE-2026-21834? +

HCL AION is affected by a vulnerability where the Content-Security-Policy (CSP) security response header was missing from application responses. Without this header, the browser does not restrict the sources of scripts and other content, increasing exposure to cross-site scripting and content-injection attacks, potentially resulting in unintended behavior or security impact under certain conditions. It has a CVSS v3.1 base score of 3.1 (LOW).

How severe is CVE-2026-21834? +

CVE-2026-21834 has a CVSS v3.1 score of 3.1 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-21834? +

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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