How severe is CVE-2023-20866?

CVE-2023-20866 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2023-20866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-20866?

CVE-2023-20866 affects Vmware Spring Session. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-20866?

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

When was CVE-2023-20866 published?

CVE-2023-20866 was published on 2023-04-13 and last updated on 2026-06-17.

CVE-2023-20866

CVE-2023-20866 is a medium-severity vulnerability in Vmware Spring Session with a CVSS 3.x base score of 6.5. 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Vmware Spring Session
Published: 2023-04-13
Last modified: 2026-06-17

Description

In Spring Session version 3.0.0, the session id can be logged to the standard output stream. This vulnerability exposes sensitive information to those who have access to the application logs and can be used for session hijacking. Specifically, an application is vulnerable if it is using HeaderHttpSessionIdResolver.

Frequently asked questions

What is CVE-2023-20866?: In Spring Session version 3.0.0, the session id can be logged to the standard output stream. This vulnerability exposes sensitive information to those who have access to the application logs and can be used for session hijacking. Specifically, an application is vulnerable if it is using HeaderHttpSessionIdResolver.
How severe is CVE-2023-20866?: CVE-2023-20866 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2023-20866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-20866?: CVE-2023-20866 affects Vmware Spring Session. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-20866?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-20866 published?: CVE-2023-20866 was published on 2023-04-13 and last updated on 2026-06-17.

References

https://spring.io/security/cve-2023-20866

Affected products (1)

cpe:2.3:a:vmware:spring_session:3.0.0:*:*:*:*:*:*:*

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