API Connect: Authentication Bypass by Spoofing
CVE-2026-19121 is a high-severity authentication bypass by spoofing vulnerability in API Connect from IBM, with a CVSS 3.1 base score of 8.3 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected API Connect versions: 12.1.0.0 through 12.1.1.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.37% 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 | 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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L. Scored by CNA (us.ibm.com).
Official description
IBM API Connect 12.1.0.0 through 12.1.1.2 could allow an authenticated attacker to gain unauthorized access due to improper authorization. Tenant context is not sufficiently verified against the authenticated user, which could allow access to another tenant's resources.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authentication Bypass by Spoofing
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
More Authentication Bypass by Spoofing vulnerabilities (CWE-290)
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 references
Other vulnerabilities in API Connect
- 7.2 High severity
- 7.5 High severity
- 9.4 Critical severity
- 9.3 Critical severity
- 9.6 Critical severity
- 7.6 High severity
Recent Authentication Bypass by Spoofing vulnerabilities
- 8.5 High severity
- 7.5 High severity
- 8.5 High severity
- 9.1 Critical severity
- 8.8 High severity
- 8.3 High severity
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