CVE-2026-45061 Budibase: SSRF via trivial `.tar.gz` substring bypass in Plugin URL upload (`/api/plugin`)
Attackers can bypass URL validation to perform Server-Side Request Forgery, potentially accessing internal resources if blacklist protections are disabled or bypassed.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-45061?
CVE-2026-45061 is a high-severity server-side request forgery vulnerability in budibase, published on 27 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Budibase is an open-source low-code platform. Prior to 3.35.10, the Plugin URL upload endpoint (POST /api/plugin) validates the submitted URL with a single substring check: url.includes(".tar.gz"). Any URL containing .tar.gz anywhere in the string — in the path, query string, or fragment — passes this check. The URL then proceeds directly to fetchWithBlacklist() with no further validation of host, scheme, or path. Standalone, this vulnerability is blocked by Budibase's default SSRF blacklist, which covers private IP ranges. But the URL validation layer itself is broken regardless, and it directly enables SSRF in two realistic situations: (1) when chained with the BLACKLIST_IPS bypass ([001]), where the blacklist is empty; and (2) when the plugin server follows HTTP redirects from an external URL to an internal target (the default node-fetch behavior with redirect: 'follow'). This vulnerability is fixed in 3.35.10.
Weakness: CWE-918
Which versions are affected by CVE-2026-45061?
2 open source packages ship an affected version, including budibase.
| Package | Affected | Fixed in |
|---|---|---|
budibase npm | All versions | 3.35.10 |
budibase npm | All versions | 3.35.10 |
How do I fix CVE-2026-45061?
Upgrade budibase to 3.35.10 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-45061 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-45061 exists.
Sources
Also known as GHSA-xh5j-727m-w6gg.