Medium severity · published Jun 11, 2026
CVE-2026-40996
Inbound WS-Security allows RSA PKCS#1 v1.5 key transport by default
4.8
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SW
Spring Web Services · Spring
5.0.0 before 5.0.1.1; 4.1.0 before 4.1.3.1; 4.0.0 before 4.0.19; 3.1.0 before 3.1.9 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40996
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40996
Vendor Advisory
https://spring.io/security/cve-2026-40996
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