# CVE-2026-98951: riscv: ptrace: Zero-initialize regset buffers before copyin

CVE-2026-98951 is fixed in linux on 1 platform by DEBIAN-CVE-2026-98951 (version 7.2.11-1), released October 24, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-98951
- Priority: High
- CVSS: 7.1 (Important)
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 23, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98951

## Description

In the Linux kernel, the following vulnerability has been resolved:  riscv: ptrace: Zero-initialize regset buffers before copyin  user_regset_copyin() only copies `count` bytes, so a PTRACE_SETREGSET request with a short iov_len leaves the rest of the stack buffer uninitialized. In riscv_vr_set() that garbage is validated and copied into the target's vstate, and in riscv_cfi_set() it can be stored as the target's shadow stack pointer. Zero both buffers, as the get path already does.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.2.11-1 | [DEBIAN-CVE-2026-98951](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98951.md) | Oct 24, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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