CVE-2026-47857: CWE-190 Integer Overflow or Wraparound in Spring Reactor Core
Description
CVE-2026-47857 is an integer overflow vulnerability in Spring Reactor Core affecting applications using the Flux.windowTimeout operator with fairBackpressure enabled. This flaw can lead to a Denial of Service (DoS) condition. The vulnerability impacts multiple versions of Reactor Core, including 3.8.0 through 3.8.6, 3.5.0 through 3.7.19, and 3.4.41 and earlier. The CVSS score is 5.9, indicating a medium severity level. No official patch or remediation guidance is currently available.
CVSS v3.1
Score 5.9medium
Affected software
Spring
Reactor Core
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability identified as CVE-2026-47857 in Spring Reactor Core involves an integer overflow or wraparound (CWE-190) when using the Flux.windowTimeout operator with fairBackpressure enabled. This condition can cause a Denial of Service (DoS) by disrupting normal application operation. Affected versions include Reactor Core 3.8.0 to 3.8.6, 3.5.0 to 3.7.19, and 3.4.41 and earlier. There is no vendor advisory or patch information provided, and no known exploits in the wild have been reported.
Potential Impact
The primary impact of this vulnerability is a Denial of Service (DoS) condition, which can disrupt availability of applications using the affected Reactor Core versions with the specified operator and configuration. There is no reported impact on confidentiality or integrity.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider avoiding the use of the Flux.windowTimeout operator with fairBackpressure enabled or implement application-level controls to mitigate potential DoS conditions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- vmware
- Date Reserved
- 2026-05-20T10:00:55.156Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a8f86faacd9273b4994706e
Added to database: 08/27/2026, 00:38:18 UTC
Last enriched: 09/10/2026, 09:39:34 UTC
Last updated: 10/10/2026, 18:48:19 UTC
Views: 81
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