CVE-2026-41853: Spring Framework Multipart Request Smuggling in Spring MVC and WebFlux

Severity: medium (CVSS 5.3 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-444

Description

Spring MVC and WebFlux applications are vulnerable to Multipart request smuggling attacks. 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
Maven Org.Springframework:Spring-Webflux: from 7.0.0 before 7.0.8; from 6.2.0 before 6.2.19; from 6.1.0 through 6.1.21; through 5.3.39; 7.0.0, 7.0.1, 7.0.2, 7.0.3, 7.0.4, 7.0.5 (+151) — fixed in 7.0.8, 6.2.19
Maven Org.Springframework:Spring-Webmvc: from 7.0.0 before 7.0.8; from 6.2.0 before 6.2.19; from 6.1.0 through 6.1.21; through 5.3.39; 7.0.0, 7.0.1, 7.0.2, 7.0.3, 7.0.4, 7.0.5 (+293) — fixed in 7.0.8, 6.2.19
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; Maven Org.Springframework:Spring-Webflux 7.0.8, 6.2.19; Maven Org.Springframework:Spring-Webmvc 7.0.8, 6.2.19; 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-2026-41853

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