CVE-2026-41850: Spring Framework Algorithmic Denial of Service via SpEL Expressions
Summary
CVE-2026-41850: Spring Framework Algorithmic Denial of Service via SpEL Expressions. Affects org.springframework:spring-expression across 4 version ranges.
< 5.3.39
>= 6.1.0, <= 6.1.21
>= 6.2.0, < 6.2.19
>= 7.0.0, < 7.0.8
Fixed in 5.3.39, 6.2.19 or 7.0.8, depending on the release line you run. How to fix ↓
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Background
The Spring Framework is a widely used application framework for building Java applications. It provides comprehensive infrastructure support for developing Java applications, allowing developers to focus on building their applications without worrying about the underlying infrastructure. One of its key features is the Spring Expression Language (SpEL), which allows querying and manipulation of objects at runtime. However, the framework is vulnerable to an Algorithmic Denial of Service (DoS) when evaluating user-supplied SpEL expressions, which can lead to excessive resource consumption and application unavailability.
Vulnerability Detail
The vulnerability arises from the way the Spring Framework evaluates user-supplied SpEL expressions. An attacker can craft a malicious expression that, when evaluated, consumes excessive CPU or memory resources. This can degrade application performance or even render it completely unavailable. The affected versions include Spring Framework 7.0.0 through 7.0.7, 6.2.0 through 6.2.18, 6.1.0 through 6.1.27, and 5.3.0 through 5.3.48. The CVSS score for this vulnerability is 7.5, indicating a high severity level.
How To Fix
Latest published version: 7.1.0-RC1 as of 22 Oct 2026
Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
< 5.3.395.3.39 -
>= 6.2.0, < 6.2.196.2.19 -
>= 7.0.0, < 7.0.87.0.8
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
As a temporary workaround, avoid evaluating user-supplied SpEL expressions or implement strict validation and sanitization of the input expressions to mitigate the risk of DoS attacks.
Conclusion
The Spring Framework vulnerability CVE-2026-41850 poses a significant risk of Algorithmic Denial of Service through SpEL expressions. It is crucial for developers to update to the patched versions of the framework to mitigate this risk and ensure application stability.
See every vulnerability recorded for org.springframework:spring-expression →
FAQ
The Spring Framework is an open-source framework for building Java applications, providing comprehensive infrastructure support for developing Java applications.
Spring Expression Language (SpEL) is a powerful expression language that supports querying and manipulating objects at runtime in the Spring Framework.
An attacker can exploit this vulnerability by providing a specially crafted SpEL expression, leading to excessive resource consumption and potential application downtime.
You can use Vulert, which monitors and alerts in real-time for open-source vulnerabilities in your software. You can check if your application is affected by this vulnerability using the Vulert playground without any signup.
If immediate updates are not possible, consider implementing strict validation and sanitization of user-supplied SpEL expressions as a temporary workaround.
Related vulnerabilities
Recent vulnerabilities recorded for org.springframework:spring-expression.
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