CVE-2026-47857 — Reactor Core windowTimeout fair-backpressure stream hang due to 20-bit index wrap-around

CVE-2026-47857

Reactor Core windowTimeout fair-backpressure stream hang due to 20-bit index wrap-around PUBLISHED

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Spring / Reactor Core	affected 3.8.0 through 3.8.6; affected 3.5.0 through 3.7.19; affected 0 through 3.4.41

CWE

No CWE identifiers supplied.

References

https://spring.io/security/cve-2026-47857

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.