# CVE-2026-8496 — SOGo

> As of 2026-08-06, CVE-2026-8496 is a MEDIUM-severity vulnerability in SOGo, CVSS v3.1 6.1, EPSS 0.5% (40.8th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-8496, most recently “Operation RoundPress: TA458 Deploys SpyPress Malware via Half-Click Webmail Zero-Days (CVE-2025-27915, CVE-2025-3929, CVE-2026-8496)”.

**Last updated:** 2026-08-06

## 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.

Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 145 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.1 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **EPSS (FIRST):** 0.5% probability of exploitation in the next 30 days, higher than 40.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-05-13, last modified 2026-08-06

## Is CVE-2026-8496 being exploited?

No public exploitation evidence for CVE-2026-8496 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-08-06. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- **Alinto SOGo**: SOGo

## How to fix CVE-2026-8496

No vendor patch reference has been recorded for CVE-2026-8496 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-8496

1 tracked threat in the Threadlinqs corpus references CVE-2026-8496, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Operation RoundPress: TA458 Deploys SpyPress Malware via Half-Click Webmail Zero-Days (CVE-2025-27915, CVE-2025-3929, CVE-2026-8496)](https://intel.threadlinqs.com/threat/TL-2026-2579) — CRITICAL · 2026-07-23

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-09-28. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [github.com](https://github.com/Alinto/sogo/commit/67ce01ec2a1a7854d8e9f615dd65afb949043e86)
- [github.com (SOGo 5.12)](https://github.com/Alinto/sogo/releases/tag/SOGo-5.12.8)
- [sogo.nu](https://www.sogo.nu/news/2026/sogo-v5128-released.html)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-8496
Full detection coverage and IOCs for threats exploiting CVE-2026-8496 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp