Vulnerability · Published Oct 15, 2026 · Assigned by GitHub_M
CVE-2026-55414NL Portal Backend Libraries: Unauthenticated form resolver forwards the privileged Objecten-API token to a caller-supplied URL (SSRF)
Medium 5.3
In plain English
A medium-severity missing authorization in nl-portal-backend-libraries from nl-portal. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
NL Portal Backend Libraries provide backend components for Dutch government portals that interact with residents, customers, suppliers, and partner organizations. From 1.1.0 until 3.0.4, and in 3.1.0, the public getFormDefinitionByObjectenApiUrl and deprecated getFormDefinitionById GraphQL resolvers are reachable without CommonGroundAuthentication and forward a caller-influenced URL through ObjectenApiService.getObjectByUrl to ObjectsApiClient.getObjectByUrl, which attaches the privileged Objecten-API token. The host-equality check restricts requests to the configured Objecten-API host but does not constrain the scheme, port, or path, allowing an unauthenticated caller to induce a token-bearing request to a chosen endpoint on that host. Standard deployments are not exposed to cross-host SSRF, token capture requires attacker-controlled routing on the configured host, and typed deserialization limits returned data to objects shaped like form definitions. The 3.0 release line is fixed in version 3.0.4. The advisory does not identify a fixed 3.1 release.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | nl.nl-portal:form | 3.0.4 | GHSA-xm3x-9cfw-jhx4 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| nl-portal | nl-portal-backend-libraries | >= 1.1.0, < 3.0.4= 3.1.0 |
Weakness: CWE-862, CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
References
- https://github.com/nl-portal/nl-portal-backend-libraries/security/advisories/GHSA-xm3x-9cfw-jhx4 x_refsource_CONFIRM
- https://github.com/nl-portal/nl-portal-backend-libraries/pull/700 x_refsource_MISC
- https://github.com/nl-portal/nl-portal-backend-libraries/commit/5ea04ef6445443e22e40a23fbed447e618b70c3f x_refsource_MISC
- https://github.com/nl-portal/nl-portal-backend-libraries/releases/tag/3.0.4.RELEASE x_refsource_MISC