Budibase: Mass Assignment in Webhook Trigger Allows Cross-Workspace Automation Execution via appId Override

published 2026-06-22 4 mo ago modified 2026-07-21 3 mo ago also EUVD-2026-39916 , GHSA-rgvg-3wpc-h44p

cvss: 8.2; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits: 0; none known

Budibase is an open-source low-code platform. Prior to 3.39.9, the webhook trigger endpoint in Budibase is publicly accessible and passes the full HTTP request body into automation execution parameters. A mass assignment vulnerability in externalTrigger() allows an attacker to overwrite the internal appId property by including it in the webhook POST body. When the automation is processed asynchronously (the default path for webhooks without a collect step), the worker executes the attacker-defined automation in the context of the victim's workspace, granting full read/write access to the victim's database. This vulnerability is fixed in 3.39.9.

Patch / fix

fixed in 2

npm @budibase/server 3.39.9
budibase budibase 3.39.9

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 4 mo ago (2026-06-29)

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/Budibase/budibase/security/advisories/GHSA-rgvg-3wpc-h44p referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.2	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
GitHub	3.1	8.2	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
NVD	3.1	9.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	@budibase/server	<3.39.9	3.39.9

Affected products

Budibase budibase

Classification

Weakness

CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes

References

github.com /Budibase/budibase/security/advisories/GHSA-rgvg-3wpc-h44p
exploit, web, mitigation, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-54351
advisory
github.com /Budibase/budibase
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary