CVE-2026-63156: XSS (CVSS 6.1)

Description

Omnispace Agora Project before 26.10.0 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious HTML attributes by manipulating the visioUrl parameter, which was not routed through the URL-sanitizing branch of the parameter filter and was urldecoded after filtering. Attackers can craft a malicious URL containing the visioUrl parameter with an attribute breakout payload to execute arbitrary JavaScript in the victim's browser pre-authentication, with the issue fixed in version 26.10.0 via changes to app/Common/Req.php.

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CVSS v3.1 Score

6.1

MEDIUM

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

EPSS — Exploit Prediction

0.0030

Probability of exploitation

0.21%

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-79 Cross-site Scripting (XSS)

References

Other References

https://github.com/xech/agora-project/releases/tag/26.10 https://www.agora-project.net/ https://www.vulncheck.com/advisories/omnispace-agora-project-reflected-xss-via-visiourl-parameter

Frequently Asked Questions

What is CVE-2026-63156? +

Omnispace Agora Project before 26.10.0 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious HTML attributes by manipulating the visioUrl parameter, which was not routed through the URL-sanitizing branch of the parameter filter and was urldecoded after filtering. Attackers can craft a malicious URL containing the visioUrl parameter with an attribute breakout payload to execute arbitrary JavaScript in the victim's browser pre-authentication, with the issue fixed in version 26.10.0 via changes to app/Common/Req.php. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2026-63156? +

CVE-2026-63156 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0030, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-63156? +

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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