CVE-2026-55549 Details.
Yamcs <=5.8.6 - Cross-Site Scripting
Atlas does not check this one. Works by exploiting the flaw.
The only reliable test for this one is to try the weakness itself, which can disturb the site. Atlas does not do that, so it does not run this check.
About CVE-2026-55549. What It Means.
Yamcs < 5.9.4 contains a stored XSS caused by inadequate HTML escaping of attacker-controlled redirect_uri parameter in authorization template, letting attackers execute JavaScript to steal authentication data, exploit requires user to open crafted URL.
Affected Product. What Is Hit.
- Vendor
- yamcs
- Product
- Yamcs
FAQ
Common Questions.
Yamcs <=5.8.6 - Cross-Site Scripting. Yamcs < 5.9.4 contains a stored XSS caused by inadequate HTML escaping of attacker-controlled redirect_uri parameter in authorization template, letting attackers execute JavaScript to steal authentication data, exploit requires user to open crafted URL.
No. The only reliable test for this one is to try the weakness itself, which can disturb the site. Atlas does not do that, so it does not run this check. The facts about CVE-2026-55549 are on this page, and you can request a demo to see how Brandefense watches your whole external attack surface.
CVE-2026-55549 is not on the CISA Known Exploited Vulnerabilities list at the time of writing, but it is still worth fixing.
Update Yamcs to the latest version from the vendor, or follow the vendor's advice to switch off the affected feature. Vendor links are listed on this page when they are known.
This page lists the public facts about CVE-2026-55549. Atlas does not run a check for it, so nothing here says whether a particular site is affected.