CVE-2026-61520 Simple Machines Forum SSRF via image proxy
Authenticated attackers can exploit an image proxy flaw in Simple Machines Forum to access internal services and cloud metadata endpoints.
- 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-2026-61520?
CVE-2026-61520 is a medium-severity server-side request forgery vulnerability in SimpleMachines SMF, published on 14 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Simple Machines Forum 2.1 prior to commit b4d23df (fixed in 2.1.8) and 3.0 prior to commit 4bf35cf contains a server-side request forgery vulnerability in the image proxy that allows authenticated attackers to trigger internal HTTP requests by embedding attacker-controlled URLs in BBCode image tags, which the proxy fetches without validating resolved destination IPs against private address ranges, loopback, or link-local addresses. Attackers can leverage SMF's automatic HMAC signature generation for any embedded image URL to obtain valid signed proxy requests targeting internal services such as cloud instance metadata endpoints, internal web applications, and container network services.
Weakness: CWE-918
Which versions are affected by CVE-2026-61520?
How do I fix CVE-2026-61520?
No fix has been published for CVE-2026-61520 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-2026-61520 being exploited?
There is no known exploitation of CVE-2026-61520 in the wild and no public exploit code.
Sources
Also known as GHSA-9wvj-rhhh-8292.