Buffer overflow in Linux

CVE-2025-21734

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Fix copy buffer page size For non-registered buffer, fastrpc driver copies the buffer and pass it to the remote subsystem. There is a problem with current implementation of page size calculation which is not considering the offset in the calculation. This might lead to passing of improper and out-of-bounds page size which could result in memory issue. Calculate page start and page end using the offset adjusted address instead of absolute address.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (10.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21734?
CVE-2025-21734 is a high-severity vulnerability in Linux, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2025-02-27.
How severe is CVE-2025-21734?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-21734 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.