CVE-2025-48990

CVE-2025-48990 is a high-severity vulnerability with a CVSS 4.0 base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-122.

Key facts

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.

Frequently asked questions

What is CVE-2025-48990?
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.
How severe is CVE-2025-48990?
CVE-2025-48990 has a CVSS 4.0 base score of 8.6, rated high severity.
Is CVE-2025-48990 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-48990?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-48990 have an EU (EUVD) identifier?
Yes. CVE-2025-48990 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-16632.
When was CVE-2025-48990 published?
CVE-2025-48990 was published on 2025-06-02 and last updated on 2026-06-17.

References

Other CWE-122 (Heap-based Buffer Overflow) vulnerabilities

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