PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-47889 Spring CVE debrief

A WebFlux application running on the Jetty 12 Core reactive adapter in Spring Framework versions 7.0.0 - 7.0.8 and 6.2.0 - 6.2.19 serializes response cookies without the sameSite attribute. This vulnerability may allow attackers to exploit this weakness, potentially leading to unauthorized access or sensitive information disclosure. Defenders responsible for Spring Framework deployments, especially those using WebFlux applications with Jetty 12 Core reactive adapter, should assess exposure and prioritize remediation efforts based on the specific configurations and potential impacts within their environments.

Vendor
Spring
Product
Spring Framework
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-27
Original CVE updated
2026-09-10
Advisory published
2026-08-27
Advisory updated
2026-09-10

Who should care

Defenders responsible for Spring Framework deployments, especially those using WebFlux applications with Jetty 12 Core reactive adapter, should assess exposure and prioritize remediation.

Why it matters

Defenders should prioritize verifying and remediating this vulnerability in their Spring Framework deployments, especially those using WebFlux applications with Jetty 12 Core reactive adapter, as it may allow attackers to exploit this vulnerability.

  • Attackers may exploit this vulnerability to steal sensitive information
  • Defenders should verify and remediate vulnerable deployments

Technical summary

The vulnerability exists in Spring Framework versions 7.0.0 - 7.0.8 and 6.2.0 - 6.2.19, where a WebFlux application running on the Jetty 12 Core reactive adapter serializes response cookies without the sameSite attribute. This omission could allow attackers to access sensitive information or perform unauthorized actions. The affected configurations involve WebFlux applications utilizing the Jetty 12 Core reactive adapter, which may be present in various deployments.

Defensive priority

Defenders should prioritize verifying and remediating this vulnerability in their Spring Framework deployments, especially those using WebFlux applications with Jetty 12 Core reactive adapter.

Recommended defensive actions

  • Verify Spring Framework version and identify deployments using WebFlux applications with Jetty 12 Core reactive adapter
  • Remediate vulnerable deployments by upgrading to a fixed version of Spring Framework
  • Monitor for potential exploitation attempts

Evidence notes

The CVE record and NVD vulnerability detail indicate that the vulnerability exists in Spring Framework versions 7.0.0 - 7.0.8 and 6.2.0 - 6.2.19. The vendor advisory provides additional information on the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-47889 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-47889

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

  • CVE-2026-47889 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-47889

    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.