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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (36.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/Activiti/Activiti/issues/5438 (issue-tracking)
- github.com/Activiti/Activiti (product)
- github.com/Activiti/Activiti/blob/7.1.0.M6/activiti-core/activiti-api-impl/acti… (technical-description)
- github.com/Activiti/Activiti/blob/7.1.0.M6/activiti-core/activiti-engine/src/ma… (technical-description)
- www.vulncheck.com/advisories/activiti-through-7.1.0-m6-expression-injection-via… (third-party-advisory)
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.