Description

NeKernal is a free and open-source operating system stack. Version 0.0.2 has a 1-byte heap overflow in `rt_copy_memory`, which unconditionally wrote a null terminator at `dst[len]`. When `len` equals the size of the destination buffer (256 bytes), that extra `'\0'` write overruns the buffer by one byte. To avoid breaking existing callers or changing the public API, the patch in commit fb7b7f658327f659c6a6da1af151cb389c2ca4ee takes a minimal approach: it simply removes the overflow-causing line without adding bounds checks or altering the function signature.

Classification

CVE ID: CVE-2025-48990

CVSS Base Severity: HIGH

CVSS Base Score: 8.6

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Affected Products

Vendor: nekernel-org

Product: nekernel

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.01% (probability of being exploited)

EPSS Percentile: 1.67% (scored less or equal to compared to others)

EPSS Date: 2025-06-07 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-48990
https://github.com/nekernel-org/nekernel/security/advisories/GHSA-jvvh-fp57-2p32
https://github.com/nekernel-org/nekernel/commit/fb7b7f658327f659c6a6da1af151cb389c2ca4ee

Timeline