CVE-2025-40292

CVE-2025-40292 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: virtio-net: fix received length check in big packets Since commit 4959aebba8c0 ("virtio-net: use mtu size as buffer length for big packets"), when guest gso is off, the allocated size for big packets is not MAX_SKB_FRAGS * PAGE_SIZE anymore but depends on negotiated MTU. The number of allocated frags for big packets is stored in vi->big_packets_num_skbfrags. Because the host announced buffer length can be malicious (e.g. the host vhost_net driver's get_rx_bufs is modified to announce incorrect length), we need a check in virtio_net receive path. Currently, the check is not adapted to the new change which can lead to NULL page pointer dereference in the below while loop when receiving length that is larger than the allocated one. This commit fixes the received length check corresponding to the new change.

Frequently asked questions

What is CVE-2025-40292?
In the Linux kernel, the following vulnerability has been resolved: virtio-net: fix received length check in big packets Since commit 4959aebba8c0 ("virtio-net: use mtu size as buffer length for big packets"), when guest gso is off, the allocated size for big packets is not MAX_SKB_FRAGS * PAGE_SIZE anymore but depends on negotiated MTU. The number of allocated frags for big packets is stored in vi->big_packets_num_skbfrags. Because the host announced buffer length can be malicious (e.g. the host vhost_net driver's get_rx_bufs is modified to announce incorrect length), we need a check in virtio_net receive path. Currently, the check is not adapted to the new change which can lead to NULL page pointer dereference in the below while loop when receiving length that is larger than the allocated one. This commit fixes the received length check corresponding to the new change.
Is CVE-2025-40292 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-40292?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-40292 have an EU (EUVD) identifier?
Yes. CVE-2025-40292 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201652.
When was CVE-2025-40292 published?
CVE-2025-40292 was published on 2025-12-08 and last updated on 2026-06-17.

References