CVE-2026-47857

MediumCVSS 5.9

Published: 27/08/2026(UTC)Updated: 28/08/2026(UTC)Translated: 27/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.22%

13th percentile - higher than 13% of all known CVEs

Summary

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

Risk Assessment

An attacker can exploit this vulnerability to overload the application, potentially leading to service unavailability.

Recommendation

Update Reactor Core to a patched version. Consider disabling fairBackpressure if not required.

Other vulnerabilities in Reactor Core

CVE-2026-47863Medium
In Reactor Core, applications using the Flux.bufferTimeout operator with fairBackpressure enabled are vulnerable to a Denial of Service (DoS) condition. Affects Reactor Core 3.8.0-3.8.6 and 3.7.19 and earlier.

Original NVD description (English source)

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