# CVE-2026-109799: Improper verification of JWT signature in IASContextProvider leads to tenant/user identity spoofing ( sap-cloud-sdk (pip))

Status: published. Published: 2026-11-10. Updated: 2026-11-10.

The SAP Cloud SDK for Python contains an improper cryptographic signature verification vulnerability (CWE-347) in IASContextProvider, the runtime-context provider registered by default via bootstrap(app).IASContextProvider extracted the app_tid, sap_gtid and user_uuid claims from the IAS JWT in the Authorization header using an unverified decoder and wrote them into the request-scoped RuntimeContext without validating the token signature. A remote caller could submit a self-signed JWT naming a victim tenant/user; the forged identity then propagated to every consumer of the runtime context:OTel span attributes (sap.tenancy.tenant_id, user.id) via RuntimeContextSpanProcessorlog records via IdentityLogFilteraudit events (tenant_id, user_initiator_id) via AuditClienttenant routing via CBCClientThis completes an earlier remediation that fixed the same unverified pattern in StarletteIASTelemetryMiddleware but did not cover IASContextProvider.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- SAP_SE / SAP Cloud SDK for Python: < 0.63.1 (affected). Source: CNA: sap

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N; source: CNA: sap

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-347

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/SAP/cloud-sdk-python/security/advisories/GHSA-93m8-crj2-v997 (CNA: sap)

- https://url.sap/sapsecuritypatchday (CNA: sap)

## Provenance

- CNA: sap: https://www.cve.org/CVERecord?id=CVE-2026-109799; retrieved 2026-11-10; source updated 2026-11-10

Revision: 7a8d16982b2dd468d3d573de371b0d0afd010516736c6728fcde4972c8ef28f6

Canonical: https://y2.dev/cve/CVE-2026-109799

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