CVE-2026-59298: Potential for improper filtering of HTTP headers in Spring Cloud Function

Severity: low (CVSS 3.5 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: 2026-08-27 · updated 2026-09-02
Weakness: CWE-20

Description

Potential for improper filtering of HTTP headers in Spring Cloud Function. Spring Cloud Function 5.0.0 - 5.0.3 Spring Cloud Function 4.3.0 - 4.3.4 Spring Cloud Function 4.2.0 - 4.2.7 Spring Cloud Function 3.2.16 and earlier

Affected products

Spring Cloud Function: from 3.2.0 before 3.2.17; from 4.2.0 before 4.2.8; from 4.3.0 before 4.3.5; from 5.0.0 before 5.0.4 — fixed in 3.2.17, 4.2.8, 4.3.5, 5.0.4
Spring Cloud Function: from 5.0.0 through 5.0.3; from 4.3.0 through 4.3.4; from 4.2.0 through 4.2.7; through 3.2.16

How to fix

Upgrade to a fixed version: Spring Cloud Function 3.2.17, 4.2.8, 4.3.5, 5.0.4. Check the vendor advisory for mitigations.

References

https://spring.io/security/cve-2026-59298

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