CVE-2026-41855: Spring Framework Unsafe Deserialization via Jackson JMS Converters

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-09 · updated 2026-07-23
Weakness: CWE-502

Description

In an untrusted JMS environment, org.springframework.jms.support.converter.MappingJackson2MessageConverter and org.springframework.jms.support.converter.JacksonJsonMessageConverter allow arbitrary class instantiation, which can lead to unauthorized actions via gadget class deserialization. Affected versions: Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.

Affected products

Spring Framework: from 5.3.0 before 5.3.49; from 6.1.0 before 6.1.28; from 6.2.0 before 6.2.18.1; from 7.0.0 before 7.0.7.1 — fixed in 5.3.49, 6.1.28, 6.2.18.1, 7.0.7.1
Spring Framework: from 7.0.0 before 7.0.7.1; from 6.2.0 before 6.2.18.1; from 6.1.0 before 6.1.28; from 5.3.0 before 5.3.49 — fixed in 7.0.7.1, 6.2.18.1, 6.1.28, 5.3.49

How to fix

Upgrade to a fixed version: Spring Framework 5.3.49, 6.1.28, 6.2.18.1, 7.0.7.1; Spring Framework 7.0.7.1, 6.2.18.1, 6.1.28, 5.3.49. Check the vendor advisory for mitigations.

References

https://spring.io/security/cve-2026-41855

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