Summary
Denial of Service in Spring Framework
Spring Framework, version 5.1, versions 5.0.x prior to 5.0.10, versions 4.3.x prior to 4.3.20, and older unsupported versions on the 4.2.x branch provide support for range requests when serving static resources through the ResourceHttpRequestHandler, or starting in 5.0 when an annotated controller returns an org.springframework.core.io.Resource. A malicious user (or attacker) can add a range header with a high number of ranges, or with wide ranges that overlap, or both, for a denial of service attack. This vulnerability affects applications that depend on either spring-webmvc or spring-webflux. Such applications must also have a registration for serving static resources (e.g. JS, CSS, images, and others), or have an annotated controller that returns an org.springframework.core.io.Resource. Spring Boot applications that depend on spring-boot-starter-web or spring-boot-starter-webflux are ready to serve static resources out of the box and are therefore vulnerable.
Impact
CVE-2018-15756 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.1.1.RELEASE, 5.0.10.RELEASE, 4.3.20.RELEASE); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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org.springframework:spring-core to 5.1.1.RELEASE or later; org.springframework:spring-core to 5.0.10.RELEASE or later; org.springframework:spring-core to 4.3.20.RELEASE or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2018-15756? CVE-2018-15756 is a high-severity security vulnerability in org.springframework:spring-core (maven), affecting versions >= 5.1.0.RELEASE, < 5.1.1.RELEASE. It is fixed in 5.1.1.RELEASE, 5.0.10.RELEASE, 4.3.20.RELEASE.
- How severe is CVE-2018-15756? CVE-2018-15756 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.springframework:spring-core are affected by CVE-2018-15756? org.springframework:spring-core (maven) versions >= 5.1.0.RELEASE, < 5.1.1.RELEASE is affected.
- Is there a fix for CVE-2018-15756? Yes. CVE-2018-15756 is fixed in 5.1.1.RELEASE, 5.0.10.RELEASE, 4.3.20.RELEASE. Upgrade to this version or later.
- Is CVE-2018-15756 exploitable, and should I be worried? Whether CVE-2018-15756 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2018-15756 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2018-15756?
- Upgrade
org.springframework:spring-coreto 5.1.1.RELEASE or later - Upgrade
org.springframework:spring-coreto 5.0.10.RELEASE or later - Upgrade
org.springframework:spring-coreto 4.3.20.RELEASE or later
- Upgrade