What’s Vulnerable › Vulnerabilities

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

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-23 · updated 2026-10-23

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.

Affected products

• Linux kernel: from 6.5.3 before 6.6; 6.6 — fixed in 6.6, 7.3

How to fix

Upgrade to a fixed version: Linux kernel 6.6, 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/59052a88ba5fe4a7bb34b3a0a42aa5d453d3bb97
• https://git.kernel.org/stable/c/89fc70d73f4ac8781f9e15edd1dbc6b6088453b3

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