CVE-2026-40939 — dsf-common-jetty
Fix: datasharingframework/dsf@f4ecb00CVE-2026-40939 is a CWE-613 vulnerability in dev.dsf:dsf-common-jetty. No vendor fix is recorded yet; mitigation options are listed below.
DSF: Missing Session Timeout for OIDC Sessions
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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
dev.dsf:dsf-common-jetty☕dev.dsf:dsf-fhir-server☕dev.dsf:dsf-bpe-serverReal-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_POLICYwhen credentials expire, prevents stale websocket connections from continuing to receive events after session timeout.
Affected Packages
| 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 dependencyDetect
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
No patched version of dev.dsf:dsf-common-jetty has shipped for CVE-2026-40939 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-40939 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-40939. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-40939 in your dependencies?
O3 Security finds CVE-2026-40939 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.