---
id: CVE-2026-62958
title: 'libriscv: Out of bounds read vuln in the ELF parser (Denial of service)'
summary: >-
  libriscv is a RISC-V sandbox and emulator. Prior to 1.18, a crafted ELF binary
  can cause out-of-bounds reads in the host emulator. `Memory<W>::binary_loader`
  checks `PT_LOAD` program-header bounds, but
  `Memory<W>::serialize_execute_segme…
severity: high
cvss: 7.9
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-20
  - CWE-125
vendor: libriscv
product: libriscv
affected:
  - libriscv < 1.18
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-02T14:54:34.516881Z'
exploitAvailable: true
published: '2026-10-30'
updated: '2026-11-02'
sourceUpdated: '2026-11-02T14:55:00.894Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-62958'
references:
  - url: >-
      https://github.com/libriscv/libriscv/security/advisories/GHSA-gm4g-6c78-gr3w
    label: >-
      https://github.com/libriscv/libriscv/security/advisories/GHSA-gm4g-6c78-gr3w
  - url: >-
      https://github.com/libriscv/libriscv/commit/61ef9ca82c8876dd80b33780893ba512af780e93
    label: >-
      https://github.com/libriscv/libriscv/commit/61ef9ca82c8876dd80b33780893ba512af780e93
  - url: >-
      https://github.com/libriscv/libriscv/commit/7bd1c189f9f9d54368cde096b07b194ad680f9fa
    label: >-
      https://github.com/libriscv/libriscv/commit/7bd1c189f9f9d54368cde096b07b194ad680f9fa
  - url: 'https://github.com/libriscv/libriscv/releases/tag/v1.18'
    label: 'https://github.com/libriscv/libriscv/releases/tag/v1.18'
tags:
  - cve.org
  - exploit-available
epss: 0.00205
epssPercentile: 0.10562
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/0Linear/CVE-2026-62958'
  checkedAt: '2026-11-07T18:22:54.659Z'
ingestedAt: '2026-11-05T19:30:42.675Z'
---

## Overview

libriscv is a RISC-V sandbox and emulator. Prior to 1.18, a crafted ELF binary can cause out-of-bounds reads in the host emulator. `Memory<W>::binary_loader` checks `PT_LOAD` program-header bounds, but `Memory<W>::serialize_execute_segment` trusts section-header `sh_offset` and `sh_size` when locating `.text` without verifying the file range against `m_binary.size()`; `Memory<W>::lookup()` has a similar section-table problem. Malformed `.text` or `.symtab` offsets can therefore bypass the program-header checks and point outside the binary buffer, crashing rvlinux. With suitable memory layout or integer overflow, out-of-buffer host heap memory may instead be mapped into the guest by `create_execute_segment()`, potentially exposing host memory. The reported reproducer demonstrates a host SIGSEGV, while memory disclosure through grooming is described as possible rather than demonstrated. This issue is fixed in version 1.18.

## Affected

- `libriscv < 1.18`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.