Symlink Attack Affecting org.springframework.boot:spring-boot package, versions [,3.5.14)[4.0.0-M1,4.0.6)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published24 Apr 2026
- disclosed23 Apr 2026
- creditUnknown
Introduced: 23 Apr 2026
CVE-2026-40977 (opens in a new tab)How to fix?
Upgrade org.springframework.boot:spring-boot to version 3.5.14, 4.0.6 or higher.
Overview
Affected versions of this package are vulnerable to Symlink Attack due to insecure handling of Process ID (PID) files. When an application uses the ApplicationPidFileWriter, it writes its PID to a predictable file system path. A local attacker with write access to the PID file's directory can create a symbolic link (symlink) at that path. When the Spring Boot application starts, it follows this symlink and overwrites the target file with its PID. This allows the attacker to corrupt or "clobber" sensitive system files, potentially leading to a denial of service or system instability.