CVE-2026-8496

Description

A cross-site scripting (XSS) vulnerability exists in Alinto SOGo, version 5.12.7. A maliciously crafted ICS calendar invitation files allows arbitrary JavaScript execution within the authenticated SOGo webmail session. The issue occurs because SVG content embedded in the description field of an ICS file, with an onrepeat event handler, is insufficiently sanitized before being rendered in the webmail interface. A remote attacker can execute JavaScript in the victim's browser when the malicious calendar invite is viewed. Successful exploitation may allow mailbox access, email and contact theft, session hijacking, and other actions allowed by an authenticated user.

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

0.0005

Probability of exploitation

0.15%

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.

References

Other References

https://github.com/Alinto/sogo/commit/67ce01ec2a1a7854d8e9f615dd65afb949043e86 https://github.com/Alinto/sogo/releases/tag/SOGo-5.12.8 https://www.sogo.nu/news/2026/sogo-v5128-released.html

Frequently Asked Questions

What is CVE-2026-8496? +

A cross-site scripting (XSS) vulnerability exists in Alinto SOGo, version 5.12.7. A maliciously crafted ICS calendar invitation files allows arbitrary JavaScript execution within the authenticated SOGo webmail session. The issue occurs because SVG content embedded in the description field of an ICS file, with an onrepeat event handler, is insufficiently sanitized before being rendered in the webmail interface. A remote attacker can execute JavaScript in the victim's browser when the malicious calendar invite is viewed. Successful exploitation may allow mailbox access, email and contact theft, session hijacking, and other actions allowed by an authenticated user. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2026-8496? +

CVE-2026-8496 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 0.0005, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-8496? +

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.