What is CVE-2026-47857?

CVE-2026-47857 is a medium-severity vulnerability in Spring Reactor Core, classified under CWE-190 INTEGER OVERFLOW OR WRAPAROUND. CVSS score: 5.9/10. Published 2026-08-27.

How severe is CVE-2026-47857?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Vulnerability in Spring Reactor Core

CVE-2026-47857

In Reactor Core, applications that use the Flux.windowTimeout operator with fairBackpressure enabled are vulnerable to a Denial of Service (DoS) condition. Reactor Core 3.8.0 - 3.8.6 Reactor Core 3.5.0 - 3.7.19 Reactor Core 3.4.41 and earlier

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Spring Reactor Core

References

security@vmware.com

Frequently asked questions

What is CVE-2026-47857?: CVE-2026-47857 is a medium-severity vulnerability in Spring Reactor Core, classified under CWE-190 INTEGER OVERFLOW OR WRAPAROUND. CVSS score: 5.9/10. Published 2026-08-27.
How severe is CVE-2026-47857?: Medium severity. CVSS v3 base score is 5.9 out of 10.