CVE-2026-40999 is a high-severity (CVSS 8.6) Server-Side Request Forgery (SSRF) vulnerability in org.springframework.ws:spring-ws-core. A fix is available for org.springframework.ws:spring-ws-core — see the affected versions and patch details below.
Spring WS SSRF via unvalidated WS-Addressing reply destinations
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40999.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-40999 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 382,795 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
org.springframework.ws:spring-ws-core☕org.springframework.ws:spring-ws-core☕org.springframework.ws:spring-ws-core☕org.springframework.ws:spring-ws-coreReal-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
When WS-Addressing is used with non-anonymous ReplyTo or FaultTo addresses, Spring WS may initiate outbound connections through configured WebServiceMessageSender instances to destinations taken directly from request headers without verifying that those destinations are safe to connect to.
Affected versions: Spring Web Services 5.0.0 through 5.0.1; 4.1.0 through 4.1.3; 4.0.0 through 4.0.18; 3.1.0 through 3.1.8.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.springframework.ws:spring-ws-core | ≥ 5.0.0&&< 5.0.2 | 5.0.2org.springframework.ws:spring-ws-core:5.0.2 |
| ☕Maven | org.springframework.ws:spring-ws-core | ≥ 4.1.0&&< 4.1.4 | 4.1.4org.springframework.ws:spring-ws-core:4.1.4 |
| ☕Maven | org.springframework.ws:spring-ws-core | ≥ 4.0.0 | No fix |
| ☕Maven | org.springframework.ws:spring-ws-core | ≥ 3.1.0 | No fix |
Affected Products
spring web servicesbroadcomDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.springframework.ws:spring-ws-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.springframework.ws:spring-ws-core to 5.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40999 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is CVE-2026-40999 in your dependencies?
Find it across Maven, including transitive dependencies.