CVE-2026-59283
Description
A flaw was found in Spring Framework. Applications that evaluate Spring Expression Language (SpEL) expressions using SimpleEvaluationContext may be vulnerable to a safety guard bypass when the SpEL expression compiler is active. This could allow an attacker to circumvent security restrictions, potentially leading to unauthorized actions within the application.
Statement
A flaw was found in Spring Framework's Spring Expression Language (SpEL) execution engine. When evaluating SpEL expressions using a SimpleEvaluationContext in compiled mode, the compiler fails to maintain safety restriction checks enforced during interpreted evaluation. A remote unauthenticated attacker can exploit this bypass by supplying crafted SpEL expressions that compile at runtime, overriding restricted method and property access controls to execute arbitrary code or unauthorized actions within the application context. Default SELinux policy constraints and non-root container isolation restrict host system access, confining primary impact to the application container layer.
Mitigation
Disable SpEL compilation globally by setting the system property `spring.expression.compiler.mode` or configuration bean setting to `OFF`. Alternatively, restrict SpEL expression input to trusted internal sources and avoid parsing untrusted user-supplied strings via `SimpleEvaluationContext`.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 9.8 | N/A | 9.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
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