CVE-2026-40942
DSF: Inverted Time Comparison in OIDC JWKS and Token Cache
The Data Sharing Framework (DSF) implements a distributed process engine based on the BPMN 2.0 and FHIR R4 standards. Prior to 2.1.0, The OIDC JWKS and Metadata Document caches used an inverted time comparison (isBefore instead of isAfter), causing the cache to never return cached values. Every incoming request triggered a fresh HTTP fetch of the OIDC Metadata Document and JWKS keys from the OIDC provider. The OIDC token cache for the FHIR client connections used an inverted time comparison (isBefore instead of isAfter), causing the cache to never invalidate. Every incoming request returned the same OIDC token even if expired. This vulnerability is fixed in 2.1.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
6.3
DSF: Inverted Time Comparison in OIDC JWKS and Token Cache
The Data Sharing Framework (DSF) implements a distributed process engine based on the BPMN 2.0 and FHIR R4 standards. Prior to 2.1.0, The OIDC JWKS and Metadata Document caches used an inverted time comparison (isBefore instead of isAfter), causing the cache to never return cached values. Every incoming request triggered a fresh HTTP fetch of the OIDC Metadata Document and JWKS keys from the OIDC provider. The OIDC token cache for the FHIR client connections used an inverted time comparison (isBefore instead of isAfter), causing the cache to never invalidate. Every incoming request returned the same OIDC token even if expired. This vulnerability is fixed in 2.1.0.
- Record
CVE-2026-40942- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-670
- Updated
- 2026-11-02
EUVDEUVD-2026-24496
6.3
The Data Sharing Framework (DSF) implements a distributed process engine based on the BPMN 2.0 and FHIR R4 standards. Prior to 2.1.0, The OIDC JWKS and Metadata Document caches used an inverted time comparison (isBefore instead of isAfter), causing the cache to never return cached values. Every incoming request triggered a fresh HTTP fetch of the OIDC Metadata Document and JWKS keys from the OIDC provider. The OIDC token cache for the FHIR client connections used an inverted time comparison (isBefore instead of isAfter), causing the cache to never invalidate. Every incoming request returned the same OIDC token even if expired. This vulnerability is fixed in 2.1.0.
- Record
EUVD-2026-24496- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-xmj9-7625-f634
6.3
Data Sharing Framework has an Inverted Time Comparison in OIDC JWKS and Token Cache
Affected Components
- DSF FHIR Server with enabled bearer-token authentication or back-channel logout.
- DSF BPE Server with enabled bearer-token authentication or back-channel logout.
- DSF BPE Server API v2 process plugins using FHIR client connections with configured OIDC authentication.
Summary
- The OIDC JWKS and Metadata Document caches used an inverted time comparison (
isBeforeinstead ofisAfter), causing the cache to never return cached values. Every incoming request triggered a fresh HTTP fetch of the OIDC Metadata Document and JWKS keys from the OIDC provider. - The OIDC token cache for the FHIR client connections used an inverted time comparison (
isBeforeinstead ofisAfter), causing the cache to never invalidate. Every incoming request returned the same OIDC token even if expired.
Impact
- Performance: Every OIDC-authenticated request added network round-trips to the OIDC provider, increasing latency
- Reliability: Cached OIDC tokens become unusable after expiration and can only be invalidated by restart of the BPE. If the OIDC provider is temporarily unreachable, all requests fail immediately instead of using cached keys
- Load: Unnecessary load on the OIDC provider, potentially causing rate limiting
Fix (commits 31c2e974d, d3ca59b4d)
- Fixed cache timeout comparison from
isBeforetoisAfterinBaseOidcClientWithCache(configuration and JWKS caches) andOidcClientWithCache(configuration, JWKS, and access token caches) - Added configurable cache timeouts via
dev.dsf.server.auth.oidc.provider.client.cache.timeout.configuration.resourceanddev.dsf.server.auth.oidc.provider.client.cache.timeout.jwks.resource(default:PT1H)
- Record
GHSA-xmj9-7625-f634- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-670
- Updated
- 2026-11-02
NVD
6.3
The Data Sharing Framework (DSF) implements a distributed process engine based on the BPMN 2.0 and FHIR R4 standards. Prior to 2.1.0, The OIDC JWKS and Metadata Document caches used an inverted time comparison (isBefore instead of isAfter), causing the cache to never return cached values. Every incoming request triggered a fresh HTTP fetch of the OIDC Metadata Document and JWKS keys from the OIDC provider. The OIDC token cache for the FHIR client connections used an inverted time comparison (isBefore instead of isAfter), causing the cache to never invalidate. Every incoming request returned the same OIDC token even if expired. This vulnerability is fixed in 2.1.0.
- Record
CVE-2026-40942- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-670
- Updated
- 2026-11-02
OSV
6.3
DSF: Inverted Time Comparison in OIDC JWKS and Token Cache
The Data Sharing Framework (DSF) implements a distributed process engine based on the BPMN 2.0 and FHIR R4 standards. Prior to 2.1.0, The OIDC JWKS and Metadata Document caches used an inverted time comparison (isBefore instead of isAfter), causing the cache to never return cached values. Every incoming request triggered a fresh HTTP fetch of the OIDC Metadata Document and JWKS keys from the OIDC provider. The OIDC token cache for the FHIR client connections used an inverted time comparison (isBefore instead of isAfter), causing the cache to never invalidate. Every incoming request returned the same OIDC token even if expired. This vulnerability is fixed in 2.1.0.
- Record
CVE-2026-40942- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-670
- Updated
- 2026-11-02
OSVGHSA-xmj9-7625-f634
6.3
Data Sharing Framework has an Inverted Time Comparison in OIDC JWKS and Token Cache
Affected Components
- DSF FHIR Server with enabled bearer-token authentication or back-channel logout.
- DSF BPE Server with enabled bearer-token authentication or back-channel logout.
- DSF BPE Server API v2 process plugins using FHIR client connections with configured OIDC authentication.
Summary
- The OIDC JWKS and Metadata Document caches used an inverted time comparison (
isBeforeinstead ofisAfter), causing the cache to never return cached values. Every incoming request triggered a fresh HTTP fetch of the OIDC Metadata Document and JWKS keys from the OIDC provider. - The OIDC token cache for the FHIR client connections used an inverted time comparison (
isBeforeinstead ofisAfter), causing the cache to never invalidate. Every incoming request returned the same OIDC token even if expired.
Impact
- Performance: Every OIDC-authenticated request added network round-trips to the OIDC provider, increasing latency
- Reliability: Cached OIDC tokens become unusable after expiration and can only be invalidated by restart of the BPE. If the OIDC provider is temporarily unreachable, all requests fail immediately instead of using cached keys
- Load: Unnecessary load on the OIDC provider, potentially causing rate limiting
Fix (commits 31c2e974d, d3ca59b4d)
- Fixed cache timeout comparison from
isBeforetoisAfterinBaseOidcClientWithCache(configuration and JWKS caches) andOidcClientWithCache(configuration, JWKS, and access token caches) - Added configurable cache timeouts via
dev.dsf.server.auth.oidc.provider.client.cache.timeout.configuration.resourceanddev.dsf.server.auth.oidc.provider.client.cache.timeout.jwks.resource(default:PT1H)
- Record
GHSA-xmj9-7625-f634- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-670
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
dev.dsf:dsf-bpe-process-api-v2Maven |
before 2.1.0 | 2.1.0 |
dev.dsf:dsf-bpe-serverMaven |
before 2.1.0 | 2.1.0 |
dev.dsf:dsf-bpe-process-api-v2Maven |
All versions, plus listed versions 2.0.02.0.0-M22.0.0-M32.0.0-M42.0.0-RC1 Show 5 moreShow less2.0.0-RC22.0.12.0.22.1.02.1.1 |
None known |
dev.dsf:dsf-bpe-serverMaven |
All versions, plus listed versions 1.0.01.0.0-M11.1.01.2.01.2.0-RC1 Show 12 moreShow less1.3.01.3.11.3.21.4.01.5.01.5.11.5.21.6.01.7.01.7.11.8.01.9.0 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-40942 is a medium vulnerability (CVSS 6.3) in Datasharingframework Dsf, published April 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 21st percentile. Fixed in dev.dsf:dsf-bpe-process-api-v2 2.1.0.
References
github.com/datasharingframework/dsf/security/advisories/GHSA-xmj9-7625-f634
github.com/datasharingframework/dsf/commit/31c2e974dfd4351756104ee8c53dbcd666192fef
github.com/datasharingframework/dsf/commit/d3ca59b4daccde16a006fedeccce28fd1f826908
nvd.nist.gov/vuln/detail/CVE-2026-40942
github.com/advisories/GHSA-xmj9-7625-f634
github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40942.json
github.com/datasharingframework/dsf