How severe is CVE-2026-41839?

CVE-2026-41839 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-41839 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-41839?

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

Does CVE-2026-41839 have an EU (EUVD) identifier?

Yes. CVE-2026-41839 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35326.

When was CVE-2026-41839 published?

CVE-2026-41839 was published on 2026-06-09 and last updated on 2026-06-23.

CVE-2026-41839

CVE-2026-41839 is a medium-severity vulnerability with a CVSS 3.x base score of 4.2. 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-384.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35326
Weakness: CWE-384
Published: 2026-06-09
Last modified: 2026-06-23

Description

A WebFlux application with a compromised subdomain (for example, compromised via cross-site scripting (XSS)) is vulnerable to an escalation attack exchanging a known session ID for that of an authenticated user. Affected versions: Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.

Frequently asked questions

What is CVE-2026-41839?: A WebFlux application with a compromised subdomain (for example, compromised via cross-site scripting (XSS)) is vulnerable to an escalation attack exchanging a known session ID for that of an authenticated user. Affected versions: Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.
How severe is CVE-2026-41839?: CVE-2026-41839 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-41839 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-41839?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-41839 have an EU (EUVD) identifier?: Yes. CVE-2026-41839 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35326.
When was CVE-2026-41839 published?: CVE-2026-41839 was published on 2026-06-09 and last updated on 2026-06-23.

References

https://spring.io/security/cve-2026-41839

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