What’s Vulnerable › Vulnerabilities
CVE-2026-41839: Spring Framework Escalation via Session Fixation in WebFlux
- Severity: medium (CVSS 4.2 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: 2026-06-09 · updated 2026-07-23
- Weakness: CWE-384
Description
A WebFlux application with a compromised subdomain (for example, compromised via cross-site scripting (XSS)) is vulnerable to an escalation attack exchanging a known session ID for that of an authenticated user. 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: before 5.3.49; from 6.1.0 before 6.1.28; from 6.2.0 before 6.2.19; from 7.0.0 before 7.0.8 — fixed in 5.3.49, 6.1.28, 6.2.19, 7.0.8
- 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, 6.2.19, 7.0.8; Spring Framework 7.0.7.1, 6.2.18.1, 6.1.28, 5.3.49. Check the vendor advisory for mitigations.
References
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