Memory exhaustion via recursive self-composition
Published Jun 1, 2026 · Updated Jun 1, 2026
Uncontrolled recursion in Spring Cloud Function allows attackers to exhaust process memory and interrupt request handling through self-composition. SimpleFunctionRegistry's FunctionInvocationWrapper.andThen accepted a wrapper with the same function definition, allowing the routing function to be composed with itself recursively. Exploitation requires a deployment to accept that self-composed function definition; the resulting recursion terminates request handling with an out-of-memory error.
Summary
What happened
Uncontrolled recursion in Spring Cloud Function allows attackers to exhaust process memory and interrupt request handling through self-composition. SimpleFunctionRegistry's FunctionInvocationWrapper.andThen accepted a wrapper with the same function definition, allowing the routing function to be composed with itself recursively. Exploitation requires a deployment to accept that self-composed function definition; the resulting recursion terminates request handling with an out-of-memory error.
The record
- CVE
- CVE-2026-40989
- Published
- Jun 1, 2026
- Updated
- Jun 1, 2026
- Vendor
- Spring
- Product
- Spring Cloud Function
- Classifications
- CWE-674, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 1, 2026CVE publishedPublication date reported by the CVE source.
- Jun 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.2.0 <3.2.16
- Affected versionversion=4.1.0 <4.1.10
- Affected versionversion=4.2.0 <4.2.6
- Affected versionversion=4.3.0 <4.3.3
- Affected versionversion=5.0.0 <5.0.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo