CVE-2026-80350 OneUptime before 12.0.7 Server-Side Request Forgery via IPv4-Mapped IPv6 Webhook URL
Authenticated users can bypass SSRF protections using IPv4-mapped IPv6 addresses to access internal services and read responses.
- 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-2026-80350?
CVE-2026-80350 is a high-severity server-side request forgery vulnerability in OneUptime, published on 26 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
OneUptime's webhook target check rejects private and loopback addresses given in IPv4 form and a small set of IPv6 forms, but has no case for the IPv4-mapped IPv6 range. The webhook delivery path calls SSRFProtection.validateWebhookTargetIsSafe, and the host-literal screening inside Common/Server/Utils/SSRFProtection.ts, performed by isBlockedHostnameLiteral, rejects private and loopback IPv4 ranges and tests an IPv6 value against the unspecified address, the loopback, the link-local prefix and the unique-local prefixes. A value such as [::ffff:127.0.0.1] matches none of them. The value is also recognised as an address literal rather than a name, so the path that re-checks addresses obtained from resolution is not taken. The HTTP client treats the mapped form as the embedded IPv4 address and connects to it, so an authenticated project member who can configure a webhook can direct the server at loopback services, private network ranges and link-local metadata endpoints, and the response is recorded where the webhook result can be read. Version 12.0.7 adds handling for the mapped range.
Weakness: CWE-918
Which versions are affected by CVE-2026-80350?
How do I fix CVE-2026-80350?
No fix has been published for CVE-2026-80350 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-2026-80350 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-80350 exists.
Sources
Also known as GHSA-7f26-9454-6r96, GHSA-9g3w-r349-3vvw.