How severe is CVE-2026-40996?

CVE-2026-40996 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-40996 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40996?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-40996 have an EU (EUVD) identifier?

Yes. CVE-2026-40996 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36206.

When was CVE-2026-40996 published?

CVE-2026-40996 was published on 2026-06-11 and last updated on 2026-06-23.

CVE-2026-40996

CVE-2026-40996 is a medium-severity vulnerability with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-327.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-36206
Weakness: CWE-327
Published: 2026-06-11
Last modified: 2026-06-23

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.

Frequently asked questions

What is CVE-2026-40996?: 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.
How severe is CVE-2026-40996?: CVE-2026-40996 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-40996 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40996?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40996 have an EU (EUVD) identifier?: Yes. CVE-2026-40996 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36206.
When was CVE-2026-40996 published?: CVE-2026-40996 was published on 2026-06-11 and last updated on 2026-06-23.

References

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

Other CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) vulnerabilities

CVE-2026-50086 — Critical (CVSS 10.0): The Aqara IAM/SSO gateway (gw-builder.aqara.com) exposes bidirectional AES round-trups against the platform's signing…
CVE-2026-21718 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in Copeland XWEB Pro version 1.12.1 and prior, enabling any attackers to…
CVE-2025-54426 — Critical (CVSS 9.9): Polkadot Frontier is an Ethereum and EVM compatibility layer for Polkadot and Substrate. In versions prior to commit…
CVE-2024-51478 — Critical (CVSS 9.9): YesWiki is a wiki system written in PHP. Prior to 4.4.5, the use of a weak cryptographic algorithm and a hard-coded…
CVE-2026-28252 — Critical (CVSS 9.8): A Use of a Broken or Risky Cryptographic Algorithm vulnerability in Trane Tracer SC, Tracer SC+, and Tracer Concierge…
CVE-2025-13476 — Critical (CVSS 9.8): Rakuten Viber Cloak mode in Android v25.7.2.0g and Windows v25.6.0.0–v25.8.1.0 uses a static and predictable TLS…

Browse all CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) vulnerabilities →