Spring Reactor Core up to 3.8.6 Flux.bufferTimeout infinite loop

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.6$0-$5k0.61+

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Spring Reactor Core up to 3.8.6. This vulnerability affects the function Flux.bufferTimeout. The manipulation leads to infinite loop. This vulnerability is uniquely identified as CVE-2026-47863. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Spring Reactor Core up to 3.8.6. This issue affects the function Flux.bufferTimeout. The manipulation with an unknown input leads to a infinite loop vulnerability. Using CWE to declare the problem leads to CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. Impacted is availability. The summary by CVE is:

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

It is possible to read the advisory at spring.io. The identification of this vulnerability is CVE-2026-47863 since 05/20/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-66828). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.6

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.9
CNA Vector (vmware): 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/20/2026 CVE reserved
08/27/2026 +99 days Advisory disclosed
08/27/2026 +0 days VulDB entry created
08/27/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: spring.io
Status: Not defined

CVE: CVE-2026-47863 (🔒)
GCVE (CVE): GCVE-0-2026-47863
GCVE (VulDB): GCVE-100-396047
EUVD: 🔒

Entryinfo

Created: 08/27/2026 02:29
Updated: 08/27/2026 05:47
Changes: 08/27/2026 02:29 (62), 08/27/2026 05:47 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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