How severe is CVE-2026-40999?

CVE-2026-40999 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-40999 being actively exploited?

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

How do I fix CVE-2026-40999?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40999 have an EU (EUVD) identifier?

Yes. CVE-2026-40999 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36209.

When was CVE-2026-40999 published?

CVE-2026-40999 was published on 2026-06-11 and last updated on 2026-06-23.

CVE-2026-40999

CVE-2026-40999 is a high-severity vulnerability with a CVSS 3.x base score of 8.6. 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-918.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-36209
Weakness: CWE-918
Published: 2026-06-11
Last modified: 2026-06-23

Description

When WS-Addressing is used with non-anonymous ReplyTo or FaultTo addresses, Spring WS may initiate outbound connections through configured WebServiceMessageSender instances to destinations taken directly from request headers without verifying that those destinations are safe to connect to. 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-2026-40999?: When WS-Addressing is used with non-anonymous ReplyTo or FaultTo addresses, Spring WS may initiate outbound connections through configured WebServiceMessageSender instances to destinations taken directly from request headers without verifying that those destinations are safe to connect to. 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-2026-40999?: CVE-2026-40999 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-40999 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40999?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40999 have an EU (EUVD) identifier?: Yes. CVE-2026-40999 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36209.
When was CVE-2026-40999 published?: CVE-2026-40999 was published on 2026-06-11 and last updated on 2026-06-23.

References

https://spring.io/security/cve-2026-40999

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