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NVD / CVE Program· CNA Linux

CVE-2026-23057: vsock/virtio: Coalesce only linear skb

—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
  • Fixed version: Linux Linux 0386bd321d0f95d041a7b3d7b07643411b044a96, 568e9cd8ed7ca9bf748c7687ba6501f29d30e59f, 63ef9b300bd09e24c57050c5dbe68feedce42e72.

Low priority for now. Upgrade to Linux Linux 0386bd321d0f95d041a7b3d7b07643411b044a96, 568e9cd8ed7ca9bf748c7687ba6501f29d30e59f, 63ef9b300bd09e24c57050c5dbe68feedce42e72 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published
Feb 4, 2026
Updated
Jun 17, 2026
EPSS
0.1% · 9th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.7affected
    • 581512a6dc939ef122e49336626ae159f3b8a345 and later · before 568e9cd8ed7ca9bf748c7687ba6501f29d30e59faffected · git
    • 581512a6dc939ef122e49336626ae159f3b8a345 and later · before 63ef9b300bd09e24c57050c5dbe68feedce42e72affected · git
    • 581512a6dc939ef122e49336626ae159f3b8a345 and later · before 0386bd321d0f95d041a7b3d7b07643411b044a96affected · git
    • before 6.7not affected · semver
    • 6.12.68 and later · up to and including 6.12.*not affected · semver
    • 6.18.8 and later · up to and including 6.18.*not affected · semver
    • 6.19 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.69-16.12.69-1
Debian:14linuxbefore 6.18.8-16.18.8-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-23055Feb 4, 2026 · i2c: riic: Move suspend handling to NOIRQ phase
    0Monitor
  • ← EarlierCVE-2026-23056Feb 4, 2026 · uacce: implement mremap in uacce_vm_ops to return -EPERM
    0Monitor
  • Later →CVE-2026-23058Feb 4, 2026 · can: ems_usb: ems_usb_read_bulk_callback(): fix URB memory leak
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0386bd321d0f95d041a7b3d7b07643411b044a96Vendor (CNA)
Linux Linux568e9cd8ed7ca9bf748c7687ba6501f29d30e59fVendor (CNA)
Linux Linux63ef9b300bd09e24c57050c5dbe68feedce42e72Vendor (CNA)
debian:linux6.12.69-1 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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