CVE-2026-23057In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: Coalesce only linear skb vsock/virtio common tries to coalesce buffers in rx queue: if a linear skb (with a spare tai…

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: Coalesce only linear skb vsock/virtio common tries to coalesce buffers in rx queue: if a linear skb (with a spare tail room) is followed by a small skb (length limited by GOOD_COPY_LEN = 128), an attempt is made to join them. Since the introduction of MSG_ZEROCOPY support, assumption that a small skb will always be linear is incorrect. In the zerocopy case, data is lost and the linear skb is appended with uninitialized kernel memory. Of all 3 supported virtio-based transports, only loopback-transport is affected. G2H virtio-transport rx queue operates on explicitly linear skbs; see virtio_vsock_alloc_linear_skb() in virtio_vsock_rx_fill(). H2G vhost-transport may allocate non-linear skbs, but only for sizes that are not considered for coalescence; see PAGE_ALLOC_COSTLY_ORDER in virtio_vsock_alloc_skb(). Ensure only linear skbs are coalesced. Note that skb_tailroom(last_skb) > 0 guarantees last_skb is linear.

CVSS

Not yet scored

Weakness (CWE)

Not given

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Not given

NVD analysis

Deferred

Record last updated

Jun 17, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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