CVE-2026-40968
Vmware Spring Grpc ≤ 1.0.3
Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:NSummary
CVE-2026-40968 is a medium-severity Improper Isolation or Compartmentalization (CWE-653) vulnerability in Vmware Spring Grpc. Its CVSS base score is 4.2 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Escape to Host (T1611); ranked at the 7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-2 (Separation of System and User Functionality) and SC-3 (Security Function Isolation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-40968 affects Spring gRPC versions 1.0.0 through 1.0.2, as well as older unsupported versions. The vulnerability arises when an authenticated user is denied access to a gRPC method, causing their authenticated identity to remain bound to the gRPC worker thread. This identity can then be inherited by a subsequent unauthenticated request processed on the same thread, potentially enabling escalated permissions. Published on 2026-04-28, it carries a CVSS v3.1 base score of 4.2 (AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N) and maps to CWE-653.
Exploitation requires an attacker with low privileges (PR:L) who can authenticate and trigger a gRPC method access denial over the network (AV:N). The lingering identity on the worker thread allows a follow-up unauthenticated request to inherit the elevated credentials, achieving limited confidentiality and integrity impacts (C:L/I:L) without availability disruption. High attack complexity (AC:H) is needed, with no user interaction required (UI:N) and no scope change (S:U).
Spring gRPC addresses the issue in version 1.0.3. Security practitioners should upgrade affected deployments and consult the official advisory at https://spring.io/security/cve-2026-40968 for full mitigation guidance and verification steps.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26054
Vulnerability Data
When an authenticated user is denied access to a gRPC method, their authenticated identity remains bound to the gRPC worker thread and can be inherited by a subsequent unauthenticated request on the same thread. This may allow the subsequent user…
more
to gain escalated permissions. Affected versions: Spring gRPC: 1.0.0 - 1.0.2 (fixed in 1.0.3). Older, unsupported versions are also affected.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 8 hardening rules · 7 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
Security function isolation is the canonical mechanism for protecting higher-privilege compartments.
Process isolation maintains separate execution domains so one process cannot affect another’s privilege level.
Explicit separation of user and management functionality implements the required compartmentalization.
System partitioning creates distinct domains that enforce isolation between differently privileged components.
Access enforcement directly requires approved authorizations to be applied to compartmentalized resources.
Information flow enforcement structurally prevents unauthorized mixing of data or functions across privilege boundaries.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Segregation of duties directly enforces separation of privilege levels and functions.
Network segregation is a classic technical control for isolating different privilege domains.
Secure system architecture principles explicitly call for isolation and least-privilege boundaries.
Separation of development, test and production environments is a direct application of compartmentalization.
Access control policies establish the boundaries that isolation must enforce.
Managing access rights is the operational mechanism for compartmentalizing privileges.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 9 (1 rule)
- V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-653
RHEL 9 (2 rules)
- V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-653
- V-272496 RHEL 9 must elevate the SELinux context when an administrator calls the sudo command. prevents CWE-653
Windows 10 (1 rule)
- V-220712 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-653
Windows 11 (1 rule)
- V-253269 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-653
Windows Server 2016 (1 rule)
- V-225007 Only administrators responsible for the member server or standalone or nondomain-joined system must have Administrator rights on the system. prevents CWE-653