CVE-2025-41243: Spring Expression language property modification using Spring Cloud Gateway Server WebFlux

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 3.5%, percentile 89: FIRST’s model estimates a 3.5% chance of exploitation activity in the next 30 days, higher than 89% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes org.springframework.cloud:spring-cloud-gateway-server-webflux (Maven) >= 3.1.0, <= 3.1.10, no fixed version listed; org.springframework.cloud:spring-cloud-gateway-server-webflux (Maven) >= 4.0.0, <= 4.1.10, no fixed version listed; org.springframework.cloud:spring-cloud-gateway-server-webflux (Maven) >= 4.2.0, < 4.2.5, fixed in 4.2.5; org.springframework.cloud:spring-cloud-gateway-server-webflux (Maven) >= 4.3.0, < 4.3.1, fixed in 4.3.1. Check your lockfile, including transitive dependencies.

What it is

Spring Cloud Gateway Server Webflux may be vulnerable to Spring Environment property modification. An application should be considered vulnerable when all the following are true: The application is using Spring Cloud Gateway Server Webflux (Spring Cloud Gateway Server WebMVC is not vulnerable). Spring Boot actuator is a dependency. The Spring Cloud Gateway Server Webflux actuator web endpoint is enabled via management.endpoints.web.exposure.include=gateway. The actuator endpoints are available to attackers. The actuator endpoints are unsecured.

From the GitHub advisory

Spring Cloud Gateway Server Webflux may be vulnerable to Spring Environment property modification.

An application should be considered vulnerable when all the following are true:

The application is using Spring Cloud Gateway Server Webflux (Spring Cloud Gateway Server WebMVC is not vulnerable). Spring Boot actuator is a dependency. The Spring Cloud Gateway Server Webflux actuator web endpoint is enabled via management.endpoints.web.exposure.include=gateway. The actuator endpoints are available to attackers. The actuator endpoints are unsecured.

Weakness type: CWE-917, CWE-94.

Product: org.springframework.cloud:spring-cloud-gateway-server-webflux (Maven) · Assigned by: vmware · Published: 2025-09-16

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 3.55% probability of exploitation activity in the next 30 days; percentile 89.

Timeline

• 2025-09-16 — CVE record published by vmware
• 2025-09-16 — GitHub-reviewed advisory GHSA-q2cj-h8fw-q4cc published (critical)
• 2026-02-26 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-q2cj-h8fw-q4cc github.com
2. CVE.org record CVE-2025-41243 cve.org
3. NVD entry CVE-2025-41243 nvd.nist.gov

Other references from the CVE record and advisory

1. spring.io spring.io

Critical Maven advisories · Today’s Security Digest