Out-of-bounds Read in Libriscv
CVE-2026-62958
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.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published .
CVSS v3 metric
CVSS v3 base score 7.9 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Libriscv — versions < 1.18
Weakness classification (CWE)
Public proof-of-concept exploits
References
Frequently asked questions
- What is CVE-2026-62958?
- CVE-2026-62958 is a high-severity vulnerability in Libriscv, classified under Improper Input Validation. CVSS score: 7.9/10. Published 2026-10-30.
- How severe is CVE-2026-62958?
- High severity. CVSS v3 base score is 7.9 out of 10.
- Is CVE-2026-62958 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.