Buffer overflow in Linux
CVE-2025-39718
In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: Validate length in packet header before skb_put() When receiving a vsock packet in the guest, only the virtqueue buffer size is validated prior to virtio_vsock_skb_rx_put(). Unfortunately, virtio_vsock_skb_rx_put() uses the length from the packet header as the length argument to skb_put(), potentially resulting in SKB overflow if the host has gone wonky. Validate the length as advertised by the packet header before calling virtio_vsock_skb_rx_put().
Vulnerability class: Buffer Overflow
EPSS: 0.001 (3.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Linux — versions 6.17, 6.16.4, 6.6.103
- Linux Linux_kernel
- Debian Debian_linux — versions 11.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
- af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)
- 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
Frequently asked questions
- What is CVE-2025-39718?
- CVE-2025-39718 is a high-severity vulnerability in Linux, classified under Out-of-bounds Write. CVSS score: 8.4/10. Published 2025-09-05.
- How severe is CVE-2025-39718?
- High severity. CVSS v3 base score is 8.4 out of 10.
- Is CVE-2025-39718 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.