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CVE-2026-23057

UnknownEPSS 0.17%

Last modified

CVE-2026-23057 is a vulnerability of currently unknown severity. 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. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

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.

Metrics

EPSS Probability
0.17%

6.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 581512a6dc939ef122e49336626ae159f3b8a345, < 568e9cd8ed7ca9bf748c7687ba6501f29d30e59f; >= 581512a6dc939ef122e49336626ae159f3b8a345, < 63ef9b300bd09e24c57050c5dbe68feedce42e72; >= 581512a6dc939ef122e49336626ae159f3b8a345, < 0386bd321d0f95d041a7b3d7b07643411b044a96
LinuxLinux6.7

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-23057?
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.
How severe is CVE-2026-23057?
Severity scoring for CVE-2026-23057 is pending analysis. The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2026-23057?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST