CVE-2026-59303: Dynamic destination cache size is not properly bound in Spring Cloud Stream

Severity: low (CVSS 3.8 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 2026-09-04
Weakness: CWE-770

Description

Dynamic destination cache size is not properly bound in Spring Cloud Stream. Spring Cloud Stream 5.0.0 - 5.0.2 Spring Cloud Stream 4.3.0 - 4.3.3 Spring Cloud Stream 4.2.0 - 4.2.6

Affected products

Spring Cloud Stream: from 4.2.0 before 4.2.7; from 4.3.0 before 4.3.4; from 5.0.0 before 5.0.3 — fixed in 4.2.7, 4.3.4, 5.0.3
Spring Cloud Stream: from 5.0.0 through 5.0.2; from 4.3.0 through 4.3.3; from 4.2.0 through 4.2.6

How to fix

Upgrade to a fixed version: Spring Cloud Stream 4.2.7, 4.3.4, 5.0.3. Check the vendor advisory for mitigations.

References

https://spring.io/security/cve-2026-59303

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