Medium
Reactor Core bufferTimeout fair-backpressure pipeline permanently hangs when upstream delivers items during an active flush
Type: advisorySources: OSV
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
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-47863
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 2 Nov 2026, 23:12 UTC · Revision 1
Source evidence
Reactor Core bufferTimeout fair-backpressure pipeline permanently hangs when upstream delivers items during an active flush
core-osv · Original sourcePublished 26 Aug 2026, 23:28 UTC
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
osv:CVE-2026-47863
Complete source record
{
"id": "eee79341f8932403a87a2d2518a74ffe49276194658c14d44abc28eaa9cb802a",
"url": "https://osv.dev/vulnerability/CVE-2026-47863",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Reactor Core bufferTimeout fair-backpressure pipeline permanently hangs when upstream delivers items during an active flush",
"summary": "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",
"evidence": "osv:CVE-2026-47863",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-47863",
"aliases": [
"CVE-2026-47863"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/reactor/reactor-core",
"type": "GIT",
"events": [
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{
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}
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"database_specific": {
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{
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}
],
"source": "DESCRIPTION"
}
]
}
}
],
"versions": [
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-47863.json"
}
}
],
"modified": "2026-10-28T02:30:24.262465461Z",
"provider": "osv",
"references": [
"https://spring.io/security/cve-2026-47863",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47863.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-47863"
],
"provider_metadata": {
"cna_assigner": "vmware",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"introduced": "3.8.0"
},
{
"last_affected": "3.8.6"
},
{
"last_affected": "3.7.19"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47863.json"
}
},
"related_cves": [
{
"value": "CVE-2026-47863",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 490773,
"published_at": "2026-08-26T23:28:48.599+00:00"
}