# CVE-2026-59298: Spring Cloud Function improper HTTP header filtering

Source: https://junglewise.ai/threats/cve-2026-59298-spring-cloud-function-improper-http-header-filtering  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-27. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-59298 · Severity: low · CVSS 3.1 · Published 2026-08-27

Spring Cloud Function is a framework for building serverless applications in Spring. Improper filtering of HTTP headers could allow attackers to manipulate request handling or bypass security controls, potentially leading to unauthorized access or information disclosure in applications relying on header-based security policies.

Technologies: [Spring Cloud Function](https://junglewise.ai/threats/technologies/cloud-function). Vendors: [Spring](https://junglewise.ai/threats/vendors/spring).

## Quick answers

**Is CVE-2026-59298 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-59298 being exploited in the wild.

**How severe is CVE-2026-59298?** Low severity, with a CVSS score of 3.1, published 27 August 2026.

**Which products and versions are affected?** Spring Cloud Function 3.2.16 and earlier, 4.2.0–4.2.7, 4.3.0–4.3.4, 5.0.0–5.0.3.

**Is there a fix for CVE-2026-59298?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-59298 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-59298?** Check whether you run Spring Cloud Function at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This vulnerability stems from improper filtering of HTTP headers in Spring Cloud Function's request processing logic. The flaw affects multiple versions across the 3.x, 4.x, and 5.x release lines. An attacker with network access to an affected application can craft malicious HTTP requests with specially crafted headers to bypass intended security controls or manipulate application behavior. The vulnerability is network-reachable and requires no authentication. Patches are available in newer versions beyond those listed as affected.

## Affected products

- Spring Cloud Function 3.2.16 and earlier, 4.2.0–4.2.7, 4.3.0–4.3.4, 5.0.0–5.0.3

## Timeline

- 2026-08-27: disclosed

## References

- [https://spring.io/security/cve-2026-59298](https://spring.io/security/cve-2026-59298)

## Related threats

- [Spring Cloud Function composition lookup function poisoning](https://junglewise.ai/threats/cve-2026-59299-spring-cloud-function-composition-lookup-function-poisoning)
- [Spring Cloud Function isSecure() implementation does not verify HTTPS scheme](https://junglewise.ai/threats/cve-2026-59297-spring-cloud-function-issecure-implementation-does-not-verify)