CVE-2026-40996Network attack vector

SOAP message compromise via RSA v1.5 key transport

Published Jun 11, 2026 · Updated Jun 11, 2026

Cryptographic weakness in affected Spring Web Services releases allows man-in-the-middle attackers to compromise protected SOAP messages. Wss4jSecurityInterceptor sets allowRSA15KeyTransportAlgorithm to true for validation RequestData, overriding WSS4J's safer default and accepting rsa-1_5 encrypted keys. Exploitation requires inbound XML encryption, a peer using RSA v1.5, and a man-in-the-middle or oracle-capable position; success exposes or alters protected message content without interrupting service.

CVSS severity4.8
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic weakness in affected Spring Web Services releases allows man-in-the-middle attackers to compromise protected SOAP messages. Wss4jSecurityInterceptor sets allowRSA15KeyTransportAlgorithm to true for validation RequestData, overriding WSS4J's safer default and accepting rsa-1_5 encrypted keys. Exploitation requires inbound XML encryption, a peer using RSA v1.5, and a man-in-the-middle or oracle-capable position; success exposes or alters protected message content without interrupting service.

The record

CVE
CVE-2026-40996
Published
Jun 11, 2026
Updated
Jun 11, 2026
Vendor
Spring
Product
Spring Web Services
Classifications
CWE-327, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 11, 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=3.1.0 <3.1.9
  2. Affected versionversion=4.0.0 <4.0.19
  3. Affected versionversion=4.1.0 <4.1.4
  4. Affected versionversion=5.0.0 <5.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Spring · Spring Web Servicesversion=3.1.0 <3.1.9; version=4.0.0 <4.0.19; version=4.1.0 <4.1.4; version=5.0.0 <5.0.2

Published CVSS scores

4.8SpringCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/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-327Use of a Broken or Risky Cryptographic Algorithm
T1557Adversary-in-the-Middle

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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