CVE-2026-13087
Description
A heap out-of-bounds write vulnerability was found in the Linux kernel's RPC-over-RDMA server reply path in net/sunrpc/xprtrdma/svc_rdma_sendto.c. When a crafted RPC-over-RDMA client sends a large NFS READ request with an empty Write list and no Reply chunk, the server linearizes the entire multi-page reply into a fixed-size 4096-byte heap buffer without bounds checking, resulting in a kernel heap overflow. This can lead to denial of service via kernel crash or potential code execution through corruption of adjacent kernel heap objects.
Statement
This Important vulnerability in the Linux kernel's RPC-over-RDMA server allows a low-privileged, authenticated NFS client to trigger a heap overflow. By sending a crafted READ request, an attacker can cause a denial of service or potentially execute arbitrary code, elevating privileges beyond typical NFS access. This affects Red Hat Enterprise Linux systems utilizing NFS/RDMA, commonly deployed in high-performance computing and datacenter environments.
Mitigation
This vulnerability requires the NFS/RDMA server to be running with CONFIG_SUNRPC_XPRT_RDMA enabled, which requires RDMA hardware (InfiniBand or RoCE). Systems that do not have RDMA hardware or do not export NFS over RDMA are not affected. If NFS/RDMA is not required, disabling or not loading the svcrdma kernel module prevents exploitation.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Acknowledgements
Red Hat would like to thank AISLE Research for reporting this issue.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
