CVE-2026-40996 PUBLISHED

Inbound WS-Security allows RSA PKCS#1 v1.5 key transport by default

Assigner: vmware
Reserved: 16.04.2026 Published: 11.06.2026 Updated: 11.06.2026

Wss4jSecurityInterceptor defaulted allowRSA15KeyTransportAlgorithm to true, overriding Apache WSS4J's safer default for validation RequestData. Inbound WS-Security decryption could therefore accept RSA PKCS#1 v1.5 (rsa-1_5) encrypted key material unless operators explicitly reconfigured the flag.

Affected versions: Spring Web Services 5.0.0 through 5.0.1; 4.1.0 through 4.1.3; 4.0.0 through 4.0.18; 3.1.0 through 3.1.8.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS Score: 4.8

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Spring
Product	Spring Web Services
Versions	Default: unaffected affected from 5.0.0 to 5.0.2 (excl.) affected from 4.1.0 to 4.1.4 (excl.) affected from 4.0.0 to 4.0.19 (excl.) affected from 3.1.0 to 3.1.9 (excl.)

References

https://spring.io/security/cve-2026-40996

Problem Types

CWE-327: Use of a Broken or Risky Cryptographic Algorithm CWE

Impacts

An attacker in a man-in-the-middle or oracle-capable position can exploit the weak RSA PKCS#1 v1.5 key transport algorithm accepted by default for inbound WS-Security decryption.