Overview
vsomeip, COVESA's open source implementation of the SOME/IP automotive communication middleware, contained a memory allocation vulnerability present in versions 3.7.3 and below. A vsomeip reliable (TCP) SOME/IP endpoint grows its receive buffer to an attacker-declared message size before validating that the declared bytes have actually been received, allowing a remote, unauthenticated peer to exhaust host memory and deny service. The issue was reported publicly as COVESA/vsomeip issue #1009 and fixed in release 3.7.4 (2026-07-06).
Description
CVE-2026-91141
vsomeip is a middleware implementation of the Scalable service-Oriented MiddlewarE over IP (SOME/IP) protocol, widely used for service-oriented communication between electronic control units (ECUs) in automotive and other embedded environments. A SOME/IP message begins with a 16-byte header that includes a 32-bit length field declaring the size of the message that follows.
A vulnerability was discovered in the handling of this length field on reliable (TCP) endpoints. When a message arrives, vsomeip grows its receive buffer to the size declared in the length field in order to read the incoming message, before confirming that those bytes have actually been received. In the default configuration, no size limit is applied to reliable endpoints, so a peer can declare a message size of up to roughly 4 GB and cause the receiver to allocate that memory. Because a freshly accepted connection reaches this path on its first message, no valid service, credentials, or SOME/IP authentication are required to trigger the allocation. The client endpoint contains the same behavior, where a malicious or compromised server can attack a connecting client.
Deployments that explicitly configure a reliable message-size limit are not affected.
This issue is publicly known. It was reported as COVESA/vsomeip issue #1009 (opened 2026-02-26) and fixed in release 3.7.4 (released 2026-07-06).
Impact
A remote, unauthenticated peer can force the host to allocate an attacker-chosen amount of memory, up to approximately 4 GB per connection, by sending a single short message on a normal TCP connection to any reachable reliable SOME/IP endpoint in the default configuration. On a memory-constrained node this can terminate the service outright: a service limited to 1.5 GB was OOM-killed by a single 16-byte message claiming a 3 GB payload. On a memory-rich host, the allocation for a single connection is released when the connection closes, so sustained memory exhaustion and denial of service follow from holding or repeating connections, each forcing its own allocation.
Solution
Upgrade to vsomeip 3.7.4 or later. This issue is fixed in release 3.7.4 (released 2026-07-06). The fix replaces the unlimited compile-time default (MESSAGE_SIZE_UNLIMITED) with a bounded DEFAULT_MAX_MESSAGE_SIZE of 10 MiB, so reliable endpoints reject an oversized declared length before growing the receive buffer even when no limit is explicitly configured. The release also adds a regression test for an oversized length field. The issue and fix are tracked publicly in COVESA/vsomeip issue #1009.
Deployments that cannot upgrade immediately should apply the following mitigations.
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Deployments can explicitly set
max-payload-size-reliable(or the equivalent per-service reliable message-size limit) to a value appropriate for the service. Endpoints with such a limit configured reject oversized declared lengths and are not affected by this issue. This is the most effective mitigation available without upgrading. -
Because the vulnerability is reachable by any host that can open a TCP connection to a reliable SOME/IP endpoint, exposure should be minimized through network segmentation. Reliable endpoints should be confined to trusted, isolated in-vehicle or lab networks, and firewall or access-control rules should limit connectivity to known, authorized peers. SOME/IP endpoints should never be exposed to untrusted or external networks.
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Operators should monitor for anomalous memory growth on services offering reliable endpoints and for unexpected or repeated inbound TCP connections to SOME/IP ports, which may indicate attempts to exploit this vulnerability.
Acknowledgements
Thank you to the Jaafer Rahmani for reporting this vulnerability. This document was written by Alexander Curtis.
Vendor Information
Other Information
| CVE IDs: | CVE-2026-91141 |
| API URL: | VINCE JSON | CSAF |
| Date Public: | 2026-10-26 |
| Date First Published: | 2026-10-26 |
| Date Last Updated: | 2026-10-26 19:11 UTC |
| Document Revision: | 2 |