CVE-2026-77351 Wallos: SSRF via Unvalidated User-Level SMTP Host in Email Notification Settings
An authenticated user can trigger server-side requests to internal networks by setting a malicious SMTP host, enabling internal service probing.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-77351?
CVE-2026-77351 is a low-severity server-side request forgery vulnerability in ellite Wallos, published on 31 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 5.0.0, Wallos lets any authenticated user store an arbitrary SMTP host — including private and cloud-metadata IP addresses — in their personal email notification settings, with no server-side SSRF validation. When the scheduled notification cron job runs, it passes the stored host directly to PHPMailer, causing the Wallos server to open an outbound TCP connection to whatever address the attacker specified. This gives a low-privileged attacker a reliable mechanism to probe internal network services from the server's perspective. This issue has been patched in version 5.0.0.
Weakness: CWE-918
Which versions are affected by CVE-2026-77351?
How do I fix CVE-2026-77351?
No fix has been published for CVE-2026-77351 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-77351 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77351 exists.
Sources
Also known as GHSA-mwqv-gv8x-9jcp.