free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NRF root SBI endpoint POST /oauth2/token contains a parser-level type-confusion bug family. The handler in NFs/nrf/internal/sbi/api_accesstoken.go reflects over models.NrfAccessTokenAccessTokenReq, special-cases only plain string and NrfNfManagementNfType fields, and treats every other field as if it were a single models.PlmnId. The parsed *models.PlmnId is then assigned with reflect.Value.Set() to whichever field name the attacker put in the form body, which panics whenever the destination field's real type is incompatible (slice, different struct, primitive). Gin recovery converts each panic into HTTP 500, but the endpoint remains remotely panicable from a single unauthenticated form-encoded request and is repeatedly triggerable. This vulnerability is fixed in 4.2.2.
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Wed, 27 May 2026 18:30:00 +0000
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Wed, 27 May 2026 16:30:00 +0000
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| Description | free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NRF root SBI endpoint POST /oauth2/token contains a parser-level type-confusion bug family. The handler in NFs/nrf/internal/sbi/api_accesstoken.go reflects over models.NrfAccessTokenAccessTokenReq, special-cases only plain string and NrfNfManagementNfType fields, and treats every other field as if it were a single models.PlmnId. The parsed *models.PlmnId is then assigned with reflect.Value.Set() to whichever field name the attacker put in the form body, which panics whenever the destination field's real type is incompatible (slice, different struct, primitive). Gin recovery converts each panic into HTTP 500, but the endpoint remains remotely panicable from a single unauthenticated form-encoded request and is repeatedly triggerable. This vulnerability is fixed in 4.2.2. | |
| Title | free5GC: NRF POST /oauth2/token structured-form parser type-confusion panic family (Reflect.Set on incompatible types) | |
| Weaknesses | CWE-20 CWE-755 CWE-843 |
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cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-05-27T17:50:51.669Z
Reserved: 2026-05-05T19:00:06.023Z
Link: CVE-2026-44325
Updated: 2026-05-27T17:49:58.523Z
Status : Undergoing Analysis
Published: 2026-05-27T17:16:37.910
Modified: 2026-05-27T19:51:27.110
Link: CVE-2026-44325
No data.
OpenCVE Enrichment
Updated: 2026-05-27T19:45:40Z