CVE-2026-109799
Received Received - Intake

Improper Cryptographic Signature Verification in SAP Cloud SDK for Python

Publication date: 2026-11-10

Last updated on: 2026-11-10

Assigner: SAP SE

Description
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.

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Meta Information

Published
2026-11-10
Last Modified
2026-11-10
Generated
2026-11-10
AI Q&A
2026-11-10
EPSS Evaluated
N/A
NVD
CVE-2026-109799
EUVD
EUVD-2026-120706

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
sap cloud_sdk_for_python to 0.63.1 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-347 The product does not verify, or incorrectly verifies, the cryptographic signature for data.

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Executive Summary

This vulnerability in the SAP Cloud SDK for Python involves improper verification of cryptographic signatures in the IASContextProvider component. It allows an attacker to submit a self-signed JWT with arbitrary claims, which are then used to forge tenant or user identities without proper validation.

Detection Guidance

Check if your SAP Cloud SDK for Python version is below 0.63.1. Inspect logs for unexpected tenant or user IDs in OTel span attributes, log records, audit events, or tenant routing. Monitor for self-signed JWTs in Authorization headers.

Impact Analysis

An attacker could impersonate a legitimate user or tenant, leading to unauthorized access, data leaks, or manipulation of system behavior. The forged identity propagates through logs, audit events, and tenant routing, affecting downstream components like OTel spans and audit clients.

Compliance Impact

This vulnerability could lead to non-compliance with GDPR and HIPAA by enabling unauthorized access to sensitive data, compromising data integrity, and failing to maintain proper audit trails due to forged identities propagating through logs and events.

Mitigation Strategies

Upgrade to SAP Cloud SDK for Python version 0.63.1 or later. If immediate upgrade is not possible, enforce JWT verification at ingress or supply a verified TokenVerifier to IASContextProvider.

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