API Connect: Improper Certificate Validation
CVE-2026-17333 is a high-severity improper certificate validation vulnerability in API Connect from IBM, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected API Connect versions: 12.1.0.0 through 12.1.1.2; 10.0.8.0 through 10.0.8.12. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.22% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of API Connect you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| IBM | API Connect | 12.1.0.0 through 12.1.1.2; 10.0.8.0 through 10.0.8.12 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N. Scored by CNA (us.ibm.com).
Official description
IBM 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 attacker to bypass authentication and inject unauthorized configuration changes due to improper certificate validation.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in API Connect
- 7.2 High severity
- 7.5 High severity
- 8.3 High severity
- 9.4 Critical severity
- 9.3 Critical severity
- 9.6 Critical severity
Recent Improper Certificate Validation vulnerabilities
- 8.0 High severity
- 9.1 Critical severity
- 7.4 High severity
- 8.0 High severity
- 7.4 High severity
- 7.7 High severity
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