CVE-2026-47857CWE-190

CVE-2026-47857

Medium · published August 27, 2026

CVSS v3.1
5.9
EPSS
0%
Percentile
29.3
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
5.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00367 · 29.3th percentile
Weakness
CWE-190 · Integer Overflow or Wraparound
Published
2026-08-27T05:17Z
Affected products (3)
ProductVersionsFixed in
broadcom/reactor_core< 3.4.423.4.42
broadcom/reactor_core≥ 3.5.0, < 3.7.203.7.20
broadcom/reactor_core≥ 3.8.0, < 3.8.6.13.8.6.1
References (1)
https://spring.io/security/cve-2026-47857 · [email protected]
EPSS history
Timeline
  • 28 AUG 06:43Z
    EPSS moved — → 0%
    epss
  • 26 AUG 23:28Z
    Reactor Core windowTimeout fair-backpressure stream hang due to 20-bit index wrap-around
    cvelistv5