CVE-2026-40987: Remote-file synchronizer in Spring Integration writes server-supplied filename under localDirectory without canonicalization

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-11 · updated 2026-09-04
Weakness: CWE-22

Description

A malicious or compromised FTP/SFTP/SMB server can write arbitrary files anywhere on the client filesystem (outside the configured local-directory) with attacker-controlled content. Affected versions: Spring Integration 7.0.0 through 7.0.4; 6.5.0 through 6.5.8; 6.4.0 through 6.4.11; 6.3.0 through 6.3.14; 5.5.0 through 5.5.20.

Affected products

Spring Integration: before 5.5.21; from 6.3.0 before 6.3.15; from 6.4.0 before 6.4.12; from 6.5.0 before 6.5.8.1; from 7.0.0 before 7.0.4.1 — fixed in 5.5.21, 6.3.15, 6.4.12, 6.5.8.1, 7.0.4.1
Spring Integration: from 7.0.0 before 7.0.4.1; from 6.5.0 before 6.5.8.1; from 6.4.0 before 6.4.12; from 6.3.0 before 6.3.15; from 5.5.0 before 5.5.21 — fixed in 7.0.4.1, 6.5.8.1, 6.4.12, 6.3.15, 5.5.21

How to fix

Upgrade to a fixed version: Spring Integration 5.5.21, 6.3.15, 6.4.12, 6.5.8.1; Spring Integration 7.0.4.1, 6.5.8.1, 6.4.12, 6.3.15. Check the vendor advisory for mitigations.

References

https://spring.io/security/cve-2026-40987

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