Introduction
A new security flaw, CVE-2025-41248, has been discovered in Spring Security, one of the most popular frameworks for securing Spring-based Java applications. This vulnerability could allow attackers to bypass method-level authorization checks, especially when using annotations such as @PreAuthorize and @PostAuthorize on generic or parameterized method types.
For developers and AppSec teams, this highlights the importance of understanding how Spring Security handles generics and method annotations and how a small flaw in type resolution can lead to major access control risks.
Key Highlights of CVE-2025-41248
- Root Cause: Misinterpretation of annotations on parameterized methods in generic hierarchies within spring-security-core.
- Impact: Certain @PreAuthorize or @PostAuthorize checks may be skipped, allowing unauthorized code execution.
- Resolution: Updated logic in UniqueSecurityAnnotationScanner now uses .toClass() instead of .resolve()to correctly match method parameter types.
What Is CVE-2025-41248?
CVE-2025-41248 is an authorization to bypass vulnerability in Spring Security’s method security mechanism, specifically within the spring-security-core package (org.springframework.security:spring-security-core).
The issue appears when applications use method-level annotations (like @PreAuthorize, @PostAuthorize, if those annotations are placed on methods in generic superclasses or generic interfaces, and those superclasses/interfaces use parameterized types with unbounded generics, the detection mechanism may fail to correctly resolve those annotations. As a consequence, security annotations might be ignored in some inheritance/type-hierarchy situations, allowing code paths that should be guarded by authorization to proceed without check.
In certain cases, Spring Security fails to detect these annotations due to a mismatch in how it resolves type hierarchies.
How the Authorization Bypass Happens
When method security is enabled (e.g., using @EnableMethodSecurity), Spring Security scans each method and its type hierarchy to locate and enforce security annotations. However, if your method exists within a generic superclass or interface that uses unbounded or parameterized types, Spring’s annotation scanning logic may fail to correctly resolve the method’s signature.
So the vulnerability arises from a mismatch (or failure) in type resolution of generic parameters when scanning for security annotations in method hierarchies. The mechanism that inspects methods for annotations does not correctly account for certain generic type parameters, causing it to think “this method doesn't have the relevant annotation” when in fact it does (via some interface or superclass). That means some checks are skipped.
Technical Details Behind the Fix
The issue was fixed in the following commits:
Before the Fix
The annotation scanning mechanism used:
ResolvableType.forMethodParameter(candidateMethod, i, sourceDeclaringClass).resolve();
to get the resolved type, but the comparison was between the raw/unresolved “root parameter types” and the resolved type. If these didn’t match exactly, the scanning might reject or ignore the annotation.
After the Fix
The updated code now uses:
ResolvableType.forMethodParameter(candidateMethod, i, sourceDeclaringClass).toClass();
By resolving types directly to their class form, the framework ensures that annotation comparisons remain accurate across different generic hierarchies. This change effectively eliminates the bypass condition and restores proper enforcement of authorization annotations.
So instead of resolving to something possibly parameterized or more abstract, they ensure get the Class-object, which matches against the root parameter types for equality.
Recommended Actions for Developers and Security Teams
To mitigate the impact of CVE-2025-41248, follow these best practices:
- Upgrade to the latest version of Spring Security that includes the patch for CVE-2025-41248.
- Review your codebase for any use of method-level annotations (@PreAuthorize, @PostAuthorize) in classes or interfaces using generics.
- Revalidate your authorization logic through regression testing. Ensure that previously protected methods remain restricted.
- Monitor related advisories — this CVE is closely associated with CVE-2025-41249, which affects the Spring Framework’s internal handling of type resolution.
Related CVE: CVE-2025-41249
CVE-2025-41248 was published in conjunction with CVE-2025-41249, which addresses similar issues in the Spring Framework core.
You can review the fix here:
Spring Framework Commit: 6d710d482a6785b069e35022e81758953afc21ff
References
Conclusion
CVE-2025-41248 is a reminder that even mature security frameworks like Spring Security can be vulnerable to subtle type-resolution issues. While the bug only occurs under specific conditions, its potential impact on authorization checks makes it a high-priority fix.
By upgrading to the latest release, validating method-level annotations, and keeping dependencies up to date, teams can ensure their Spring-based applications remain resilient against authorization bypass attacks.
FAQ
Q1: What is CVE-2025-41248?
CVE-2025-41248 is an authorization bypass vulnerability in Spring Security that affects method-level annotations on parameterized types. It allows security annotations like @PreAuthorize to be ignored under specific inheritance conditions.
Q2: Which Spring Security versions are affected?
Versions prior to the patched releases of Spring Security Core are affected. Users should upgrade to the latest version to avoid exposure.
Q3: How does the vulnerability occur?
It happens when the framework fails to resolve generic method types correctly, causing the annotation scanner to miss access control annotations.
Q4: How can developers fix CVE-2025-41248?
Upgrade to the patched version of Spring Security that includes the fix. Review all generic superclass or interface methods that use security annotations.
Q5: Is this related to any other vulnerability?
Yes, it is closely related to CVE-2025-41249, which addresses a similar issue in the Spring Framework core.
