How severe is CVE-2026-40939?

No CVSS score has been assigned to CVE-2026-40939 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-40939?

CVE-2026-40939 affects the following packages: dev.dsf:dsf-common-jetty (Maven), dev.dsf:dsf-fhir-server (Maven), dev.dsf:dsf-bpe-server (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-40939?

The records we use list no patched version of dev.dsf:dsf-common-jetty for CVE-2026-40939. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

How do I detect CVE-2026-40939 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dev.dsf:dsf-common-jetty, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-40939 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-40939 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-40939 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-40939?

CVE-2026-40939 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 5th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-40939?

CVE-2026-40939 is classified as CWE-613 (CWE-613). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-40939 published, and has it been updated?

CVE-2026-40939 was published on April 21, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

CVE-2026-40939 — dsf-common-jetty

Fix: datasharingframework/dsf@f4ecb00

CVE-2026-40939 is a CWE-613 vulnerability in dev.dsf:dsf-common-jetty. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

DSF: Missing Session Timeout for OIDC Sessions

Also known asGHSA-gj7p-595x-qwf5

Published

Apr 21, 2026

Updated

Oct 28, 2026

Affected

3 pkgs

Patched

See advisory

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40939.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs5th percentile — riskier than 5% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

3 pkgs affected

☕dev.dsf:dsf-common-jetty☕dev.dsf:dsf-fhir-server☕dev.dsf:dsf-bpe-server

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Affected Components

DSF FHIR Server with enabled OIDC authentication. DSF BPE Server with enabled OIDC authentication.

Summary

OIDC-authenticated sessions had no configured maximum inactivity timeout. Sessions persisted indefinitely after login, even after the OIDC access token expired.

Impact

If a user logs in via OIDC and leaves their browser without explicitly logging out, the session remains valid indefinitely. Another person using the same browser can access the DSF UI with the previous user's permissions. This is a realistic threat in hospital environments with shared workstations.

Only affects OIDC browser sessions, not relevant for mTLS machine-to-machine communication.

Fix (commits f4ecb00, 7d25fea)

Added configurable session timeout via dev.dsf.server.auth.oidc.session.timeout (default: PT30M).
Enabled logoutWhenIdTokenIsExpired(true) in OpenID configuration to tie session lifetime to token lifetime.
Websocket sessions are now closed with VIOLATED_POLICY when credentials expire, prevents stale websocket connections from continuing to receive events after session timeout.

Affected Packages

3 total

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`dev.dsf:dsf-common-jetty`	all versions	No fix
☕Maven	`dev.dsf:dsf-fhir-server`	all versions	No fix
☕Maven	`dev.dsf:dsf-bpe-server`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dev.dsf:dsf-common-jetty, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of dev.dsf:dsf-common-jetty for CVE-2026-40939. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### Affected Components DSF FHIR Server with enabled [OIDC authentication](https://dsf.dev/operations/v2.1.0/fhir/oidc.html). DSF BPE Server with enabled [OIDC authentication](https://dsf.dev/operations/v2.1.0/bpe/oidc.html). ### Summary OIDC-authenticated sessions had no configured maximum inactivity timeout. Sessions persisted indefinitely after login, even after the OIDC access token expired. ### Impact If a user logs in via OIDC and leaves their browser without explicitly logging out, the session remains valid indefinitely. Another person using the same browser can access the DSF UI with

O3 Security · Impact-Aware SCA

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