RCE in Activiti

CVE-2026-91145

Activiti through 7.1.0.M6 fails to validate hash-brace deferred expressions in process variables, allowing attackers to bypass expression filtering. Attackers can inject expressions beginning with #{ that are stored and later evaluated in the full Spring context when a mail task uses variable-backed body fields, enabling method invocation on application beans.

Vulnerability class: Log4Shell (CVE-2021-44228)

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-91145?
CVE-2026-91145 is a high-severity vulnerability in Activiti, classified under Improper Neutralization of Special Elements used in an Expression Language Statement (Expression Language Injection). CVSS score: 7.1/10. Published 2026-09-14.
How severe is CVE-2026-91145?
High severity. CVSS v3 base score is 7.1 out of 10.