Advisory · CVE-2026-17299
IBM API Connect external reference flaw allows arbitrary file reads and SSRF
IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 lets a remote authenticated attacker perform arbitrary file reads and server-side request forgery because externally referenced content in submitted definitions is resolved without restriction, rated critical at CVSS 9.6.
- Vendor
- IBM
- Product
- API Connect
- Identifier / CWE
- CVE-2026-17299
CWE-918 - Action timing
- Immediate
Explain it like I’m five
API Connect lets you submit API definitions that point at outside files, and it fetches whatever they point at. An attacker can point a definition at a private file or an internal service and have the server read it and hand the contents back.
- 01Definition submitted
A remote authenticated attacker submits an API definition containing an external reference.
- 02Reference resolved freely
Externally referenced content is not sufficiently restricted when API Connect processes the definition.
- 03File read and SSRF
The server reads arbitrary files and makes requests to internal services on the attacker's behalf.
- 04Contents returned
The retrieved content is returned to the attacker.
What happened
IBM disclosed CVE-2026-17299 as part of a multi-vulnerability API Connect bulletin: API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow a remote authenticated attacker to perform arbitrary file reads and server-side request forgery due to unrestricted resolution of external references. Externally referenced content in submitted definitions is not sufficiently restricted when processed, and the retrieved content could be returned to the attacker. The record rates it critical at CVSS 9.6 under version 3.1, with network attack vector, low complexity, low privileges required, and changed scope.
This is one of about 98 CVEs in the same IBM API Connect bulletin; this advisory covers only this CVE. The bulletin text read for this run does not state a fixed release version, so none is claimed here. An API definition is a document the platform is built to fetch, which makes this a file-read and internal-network path disguised as normal use.
What to do
- Inventory IBM API Connect deployments and record each version, including management, gateway, and analytics components.
- Apply the fix from IBM’s security bulletin for the affected release lines.
- Until patched, restrict network access to the API Connect management and gateway interfaces and treat them as untrusted-input surfaces.
- Review access and audit logs for token use by unexpected users, unexpected administrative operations, and requests to internal or metadata addresses.
- Rotate API keys, tokens, and credentials if misuse or unauthorized access cannot be excluded.
- Verify the deployed version after updating.
Management note
A definition that the server fetches on your behalf is a read primitive for anything the server can reach. Patch, then check logs for definitions that referenced local files or internal addresses.