How severe is CVE-2026-53405?

CVE-2026-53405 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-53405 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-53405?

CVE-2026-53405 affects Apache Syncope. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-53405?

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

When was CVE-2026-53405 published?

CVE-2026-53405 was published on 2026-07-20 and last updated on 2026-07-27.

CVE-2026-53405

CVE-2026-53405 is a critical-severity vulnerability in Apache Syncope with a CVSS 3.x base score of 9.8. 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-653.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-653
Affected product: Apache Syncope
Published: 2026-07-20
Last modified: 2026-07-27

Description

Improper Isolation or Compartmentalization vulnerability in Apache Syncope. An administrator with adequate entitlements can import arbitrary BPMN process definitions via the REST API and then start the process. When a BPMN process containing a Groovy scriptTask is imported and started, the Groovy script is executed directly on the server, with no sandbox. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.6, from 4.1.0-M0 through 4.1.1. Users are recommended to upgrade to version 4.0.7 / 4.1.2, which fix this issue by wrapping Flowable's Groovy scriptTasks with security sandbox.

Frequently asked questions

What is CVE-2026-53405?: Improper Isolation or Compartmentalization vulnerability in Apache Syncope. An administrator with adequate entitlements can import arbitrary BPMN process definitions via the REST API and then start the process. When a BPMN process containing a Groovy scriptTask is imported and started, the Groovy script is executed directly on the server, with no sandbox. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.6, from 4.1.0-M0 through 4.1.1. Users are recommended to upgrade to version 4.0.7 / 4.1.2, which fix this issue by wrapping Flowable's Groovy scriptTasks with security sandbox.
How severe is CVE-2026-53405?: CVE-2026-53405 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-53405 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-53405?: CVE-2026-53405 affects Apache Syncope. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-53405?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-53405 published?: CVE-2026-53405 was published on 2026-07-20 and last updated on 2026-07-27.

References

Affected products (1)

cpe:2.3:a:apache:syncope:*:*:*:*:*:*:*:*

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