CVE-2026-71271 Memos Webhook SSRF via 0.0.0.0 Reserved-IP Bypass
Attackers can bypass IP restrictions to access internal services via webhook URL validation flaws in Memos.
- 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-2026-71271?
CVE-2026-71271 is a high-severity server-side request forgery vulnerability in usememos memos, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Memos' webhook URL validation, isReservedIP (internal/webhook/validate.go), checks a candidate IP against a reservedCIDRs list that omits 0.0.0.0/8 and never calls ip.IsUnspecified — unlike the correctly implemented sibling function isInternalIP in internal/httpgetter/html_meta.go, which does.
Weakness: CWE-918
Which versions are affected by CVE-2026-71271?
How do I fix CVE-2026-71271?
No fix has been published for CVE-2026-71271 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-2026-71271 being exploited?
There is no known exploitation of CVE-2026-71271 in the wild and no public exploit code.
Sources
Also known as GHSA-jjh5-p3gc-84xr.