# CVE-2026-18490: IBM Financial Transaction Manager RCE via Java deserialization

Source: https://junglewise.ai/threats/cve-2026-18490-ibm-financial-transaction-manager-ftm-for-redhat-openshift-is  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-23. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-18490 · Severity: high · CVSS 8.8 · Published 2026-09-23

IBM Financial Transaction Manager, used to manage payment transactions and business rules in banking environments, contains a critical vulnerability in its PayDir Business Rules Manager component that allows attackers on the adjacent network to execute arbitrary code without credentials. Exploitation grants attackers access to payment credentials and enables them to manipulate payment business rules, potentially redirecting or blocking transactions.

Technologies: [IBM Financial Transaction Manager](https://junglewise.ai/threats/technologies/financial-transaction-manager). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-18490 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18490 being exploited in the wild.

**How severe is CVE-2026-18490?** High severity, with a CVSS score of 8.8, published 23 September 2026.

**Which products and versions are affected?** IBM Financial Transaction Manager 4.x.

**Is there a fix for CVE-2026-18490?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-18490 attacked?** It is attacked from the adjacent network, in a hosted service.

**Am I affected by CVE-2026-18490?** Check whether you run IBM Financial Transaction Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an unauthenticated remote code execution flaw in the PayDir Business Rules Manager RMI SSL endpoint (BrmRMISSLServerSocketFactory.java:95, EP8) caused by unsafe Java native deserialization of untrusted data. An adjacent-network attacker can deliver a crafted serialized payload to trigger arbitrary code execution without authentication, exposing PayDir credentials and allowing unauthorized manipulation of payment rules.

## Affected products

- IBM Financial Transaction Manager 4.x

## Timeline

- 2026-09-23: disclosed

## References

- [https://www.ibm.com/support/pages/node/7288641](https://www.ibm.com/support/pages/node/7288641)

## Related threats

- [IBM Financial Transaction Manager XML external entity injection](https://junglewise.ai/threats/cve-2026-93030-ftm-4-x-all-could-allow-a-remote-authenticated-attacker-to-obtain)
- [IBM Financial Transaction Manager missing authentication in Business Rules Manager](https://junglewise.ai/threats/cve-2026-19267-ibm-financial-transaction-manager-ftm-for-redhat-openshift-is)
- [IBM Financial Transaction Manager boolean-based SQL injection](https://junglewise.ai/threats/cve-2026-19179-ibm-financial-transaction-manager-ftm-for-redhat-openshift-could)
- [IBM Financial Transaction Manager privilege escalation in container](https://junglewise.ai/threats/cve-2026-19087-ibm-financial-transaction-manager-ftm-for-redhat-openshift-could)
- [IBM Financial Transaction Manager RAG poisoning via unauthenticated runbook](https://junglewise.ai/threats/cve-2026-18875-ibm-financial-transaction-manager-ftm-for-redhat-openshift-is)