How severe is CVE-2026-21665?

CVE-2026-21665 has a CVSS 4.0 base score of 7.7, rated high severity.

Is CVE-2026-21665 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-21665?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-21665 have an EU (EUVD) identifier?

Yes. CVE-2026-21665 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7470.

When was CVE-2026-21665 published?

CVE-2026-21665 was published on 2026-02-23 and last updated on 2026-06-17.

CVE-2026-21665

CVE-2026-21665 is a high-severity vulnerability with a CVSS 4.0 base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: High (CVSS 4.0 base score 7.7)
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-7470
Weakness: CWE-502
Published: 2026-02-23
Last modified: 2026-06-17

Description

The Print Service component of Fiserv Originate Loans Peripherals (formerly Velocity Services) in unsupported version 2021.2.4 (build 4.7.3155.0011) uses deprecated .NET Remoting TCP channels that allow unsafe deserialization of untrusted data. When these services are exposed to an untrusted network in a client-managed deployment, an unauthenticated attacker can achieve remote code execution. Version 2021.2.4 is no longer supported by Fiserv. Customers should upgrade to a currently supported release (2025.1 or later) and ensure that .NET Remoting service ports are not exposed beyond trusted network boundaries. This CVE documents behavior observed in a client-hosted deployment running an unsupported legacy version of Originate Loans Peripherals with .NET Remoting ports exposed to an untrusted network. This is not a default or supported configuration. Customers running legacy versions should upgrade to a currently supported release and ensure .NET Remoting ports are restricted to trusted network segments. The finding does not apply to Fiserv-hosted environments.

Frequently asked questions

What is CVE-2026-21665?: The Print Service component of Fiserv Originate Loans Peripherals (formerly Velocity Services) in unsupported version 2021.2.4 (build 4.7.3155.0011) uses deprecated .NET Remoting TCP channels that allow unsafe deserialization of untrusted data. When these services are exposed to an untrusted network in a client-managed deployment, an unauthenticated attacker can achieve remote code execution. Version 2021.2.4 is no longer supported by Fiserv. Customers should upgrade to a currently supported release (2025.1 or later) and ensure that .NET Remoting service ports are not exposed beyond trusted network boundaries. This CVE documents behavior observed in a client-hosted deployment running an unsupported legacy version of Originate Loans Peripherals with .NET Remoting ports exposed to an untrusted network. This is not a default or supported configuration. Customers running legacy versions should upgrade to a currently supported release and ensure .NET Remoting ports are restricted to trusted network segments. The finding does not apply to Fiserv-hosted environments.
How severe is CVE-2026-21665?: CVE-2026-21665 has a CVSS 4.0 base score of 7.7, rated high severity.
Is CVE-2026-21665 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-21665?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-21665 have an EU (EUVD) identifier?: Yes. CVE-2026-21665 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7470.
When was CVE-2026-21665 published?: CVE-2026-21665 was published on 2026-02-23 and last updated on 2026-06-17.

References

https://learn.microsoft.com/en-us/dotnet/core/compatibility/core-libraries/5.0/remoting-apis-obsolete

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