# CVE-2026-62958: libriscv: Out of bounds read vuln in the ELF parser (Denial of service)

Status: published. Published: 2026-10-30. Updated: 2026-11-02.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- libriscv / libriscv: < 1.18 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 7.9 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.21% as of 2026-11-02; percentile 10.50%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-20, CWE-125

## Exploit evidence

- exploit: https://github.com/libriscv/libriscv/security/advisories/GHSA-gm4g-6c78-gr3w (ADP: CISA-ADP)

## References

- https://github.com/libriscv/libriscv/security/advisories/GHSA-gm4g-6c78-gr3w (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/libriscv/libriscv/commit/61ef9ca82c8876dd80b33780893ba512af780e93 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/libriscv/libriscv/commit/7bd1c189f9f9d54368cde096b07b194ad680f9fa (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/libriscv/libriscv/releases/tag/v1.18 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/libriscv/libriscv/security/advisories/GHSA-gm4g-6c78-gr3w (ADP: CISA-ADP; exploit)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-62958; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-62958; retrieved 2026-11-02; source updated Not reported

Revision: 5beeefb6681213a4210a463c0e210aff6e9fecbb94d0d429f1195a46c88163cd

Canonical: https://y2.dev/cve/CVE-2026-62958

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