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CVE-2026-41855 Spring CVE debrief

CVE-2026-41855 is a high-severity vulnerability affecting Spring Framework versions 7.0.0 through 7.0.7, 6.2.0 through 6.2.18, 6.1.0 through 6.1.27, and 5.3.0 through 5.3.48. The vulnerability is caused by the `MappingJackson2MessageConverter` and `JacksonJsonMessageConverter` classes in the `org.springframework.jms.support.converter` package, which allow arbitrary class instantiation in untrusted JMS environments. This can lead to unauthorized actions via gadget class deserialization.

Vendor
Spring
Product
Spring Framework
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-06-29
Advisory published
2026-06-09
Advisory updated
2026-06-29

Who should care

Users of affected Spring Framework versions should be concerned about this vulnerability, as it can be exploited in untrusted JMS environments.

Technical summary

The vulnerability has a CVSS score of 8.1 and is classified as HIGH severity. It is caused by the deserialization of gadget classes in untrusted JMS environments, which can lead to unauthorized actions.

Defensive priority

HIGH

Recommended defensive actions

  • Upgrade to a non-vulnerable version of Spring Framework.
  • Use a trusted JMS environment to prevent exploitation.
  • Implement additional security measures to prevent gadget class deserialization.

Evidence notes

The CVE record and NVD detail pages provide additional information about the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-41855 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-41855

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-41855 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-41855

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.