We are seeing reports of a cross site scripting vulnerability affecting Alinto SOGo 5.12.3/5.12.4 as of Feb 24, 2026.

Severity and Technical Details

According to News Source, CVSS score is 5.3 (medium) and the vulnerability was discovered on Feb 24, 2026. The exploitation can be initiated remotely via manipulation of the argument hint leading to cross site scripting. First, the attacker injects malicious code into the application’s input field; initially, the system fails to sanitize this input, subsequently exposing sensitive user data. Specifically, the compromised function allows attackers to execute arbitrary scripts in the context of a logged-in user.

Who Is at Risk?

Most importantly, mid-market enterprises that rely on Alinto SOGo for email and communication services are at risk. In particular, CISOs and system administrators must review their deployments promptly. Moreover, organizations handling personal data under GDPR or HIPAA regulations may face compliance violations if sensitive information is leaked. Therefore, the impact extends beyond technical security to regulatory accountability.

Background and Industry Context

Notably, similar cross-site scripting vulnerabilities have been reported in other email clients such as Microsoft Outlook and Gmail. Similarly, attackers have exploited argument hints in web applications for remote injection. In fact, the evolution of threat actors shows a persistent focus on exploiting input validation weaknesses across platforms.

Potential Impact

Currently, an estimated 10–30% of vulnerable systems could be affected if Alinto SOGo is deployed without patching. Once compromised, user credentials and internal communications may be exposed. Meanwhile, attackers can gain unauthorized access to confidential data, potentially disrupting business operations. Consequently, based on the reported severity, organizations should anticipate potential operational downtime and reputational damage.

Immediate Mitigation Steps

Immediately, upgrade to Alinto SOGo 5.12.5 or later is recommended. Specifically, patch versions 5.12.5 and 5.12.6 address the identified flaw. Next, apply the patch within 24 hours to mitigate risk. However, if immediate deployment is not feasible, consider disabling the affected function temporarily until a patch is available. Additionally, after patching, verify that input sanitization routines are active by running automated tests and monitoring for any anomalous script execution. After successful verification, maintain regular vulnerability scans.

Additional Resources

Additional resources: News Source – https://cvefeed.io/vuln/detail/CVE-2026-3054 provides further details on CVSS, affected products, timeline, and more.

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