AIKIDO-2026-224455
reactor-core is vulnerable to Denial of Service (DoS)
59
Medium Risk
This Affects:
reactor-coreTL;DR
reactor-core Flux.bufferTimeout with fair backpressure can hang when upstream items arrive during an active flush. The race leaves items buffered without scheduling a timeout, so the stream stops processing. An attacker who can influence delivery rate can exhaust subscriptions. The patch keeps flush and upstream delivery from corrupting operator state.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range and you use Flux.bufferTimeout with fair backpressure enabled.
Background info
reactor-core is vulnerable to Denial of Service (DoS) in versions 0.0.1 - 3.8.6.
How to fix this
Upgrade the io.projectreactor:reactor-core library to the patch version.
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SOC 2Compliant
ISO 27001Compliant