CVE-2026-40989
MEDIUMSelf Routing guard bypassed via function composition
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
org.springframework.cloud:spring-cloud-function-context☕org.springframework.cloud:spring-cloud-function-context☕org.springframework.cloud:spring-cloud-function-context☕org.springframework.cloud:spring-cloud-function-context☕org.springframework.cloud:spring-cloud-function-contextReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Under infinite recursion in the routing layer, request-handling can cause OOM error.
Affected Spring Products and Versions: Spring Cloud Function 3.2.x: versions prior to 3.2.16 Spring Cloud Function 4.1.x: versions prior to 4.1.10 Spring Cloud Function 4.2.x: versions prior to 4.2.6 Spring Cloud Function 4.3.x: versions prior to 4.3.3 Spring Cloud Function 5.0.x: versions prior to 5.0.2 Older, unsupported versions are also affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.springframework.cloud:spring-cloud-function-context | ≥ 4.3.0&&< 4.3.3 | 4.3.3 |
| ☕Maven | org.springframework.cloud:spring-cloud-function-context | ≥ 5.0.0&&< 5.0.2 | 5.0.2 |
| ☕Maven | org.springframework.cloud:spring-cloud-function-context | ≥ 3.2.10 | No fix |
| ☕Maven | org.springframework.cloud:spring-cloud-function-context | ≥ 4.1.0 | No fix |
| ☕Maven | org.springframework.cloud:spring-cloud-function-context | ≥ 4.2.0 | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.springframework.cloud:spring-cloud-function-context. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.springframework.cloud:spring-cloud-function-context to 4.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40989 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-40989 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-40989. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-40989 in your dependencies?
O3 detects CVE-2026-40989 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.