CVE-2026-47845Network attack vector

Remote IP spoofing via HAProxy address mis-evaluation

Published Aug 26, 2026 · Updated Aug 27, 2026

Authentication bypass in Spring Reactor Netty allows remote attackers to spoof their source IP when HAProxy Protocol is enabled. Spring has not published the specific parser or address-selection operation that mis-evaluates the HAProxy-supplied address. The application must enable HAProxy Protocol; the forged address can subvert IP-based trust decisions, with no reported confidentiality or availability impact.

CVSS severity5.3
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Spring Reactor Netty allows remote attackers to spoof their source IP when HAProxy Protocol is enabled. Spring has not published the specific parser or address-selection operation that mis-evaluates the HAProxy-supplied address. The application must enable HAProxy Protocol; the forged address can subvert IP-based trust decisions, with no reported confidentiality or availability impact.

The record

CVE
CVE-2026-47845
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
Spring
Product
Reactor Netty
Classifications
CWE-290
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.0.52
  2. Affected versionversion=1.1.0 <=1.2.18
  3. Affected versionversion=1.3.0 <=1.3.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Spring · Reactor Nettyversion=0 <=1.0.52; version=1.1.0 <=1.2.18; version=1.3.0 <=1.3.6

Published CVSS scores

5.3VMwareCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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