Vulnerability in Orphan-Oss Ognl

CVE-2026-113730

OGNL is an Object Graph Navigation Library for Java. Prior to 3.4.13, the optional stricter-invocation mode in OgnlRuntime.invokeMethod checks the declaring class of the method that OGNL invokes but does not block java.lang.reflect.Method, java.lang.reflect.Constructor, or java.lang.reflect.Field. An attacker-controlled expression can invoke one of these reflection objects as a proxy for a method on a blocked class, causing the real operation to execute inside JDK reflection without passing through the stricter-invocation check again. Exploitation requires an application to evaluate untrusted OGNL expressions, use the default or an equivalently permissive MemberAccess that permits reflection, and rely on stricter invocation as a sandbox. Applications using a restrictive MemberAccess, including Apache Struts with SecurityMemberAccess, are not affected by this bypass. This issue is fixed in 3.4.13.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-113730?
CVE-2026-113730 is a medium-severity vulnerability in Orphan-Oss Ognl, classified under Protection Mechanism Failure. CVSS score: 5.6/10. Published 2026-10-20.
How severe is CVE-2026-113730?
Medium severity. CVSS v3 base score is 5.6 out of 10.