Vulnerability in Spring Reactor Core

CVE-2026-47863

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

References

Frequently asked questions

What is CVE-2026-47863?
CVE-2026-47863 is a medium-severity vulnerability in Spring Reactor Core, classified under CWE-835 LOOP WITH UNREACHABLE EXIT CONDITION ('INFINITE LOOP'). CVSS score: 5.9/10. Published 2026-08-27.
How severe is CVE-2026-47863?
Medium severity. CVSS v3 base score is 5.9 out of 10.