Medium 5.5Published Feb 4, 2026

CVE-2026-23069vsock/virtio: fix potential underflow in virtio_transport_get_credit()

Updated under an hour ago (Oct 27, 2026, 10:00 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix potential underflow in virtio_transport_get_credit() The credit calculation in virtio_transport_get_credit() uses unsigned arithmetic: ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt); If the peer shrinks its advertised buffer (peer_buf_alloc) while bytes are in flight, the subtraction can underflow and produce a large positive value, potentially allowing more data to be queued than the peer can handle. Reuse virtio_transport_has_space() which already handles this case and add a comment to make it clear why we are doing that. [Stefano: use virtio_transport_has_space() instead of duplicating the code] [Stefano: tweak the commit message]

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-190
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 06a8fc78367d070720af960dcecec917d3ae5f3b before d96de882d6b99955604669d962ae14e94b66a551; 06a8fc78367d070720af960dcecec917d3ae5f3b builds before 02f9af192b98d15883c70dd41ac76d1b0217c899; from 06a8fc78367d070720af960dcecec917d3ae5f3b before d05bc313788f0684b27f0f5b60c52a844669b542; from 06a8fc78367d070720af960dcecec917d3ae5f3b before ec0f1b3da8061be3173d1c39faaf9504f91942c3; 06a8fc78367d070720af960dcecec917d3ae5f3b builds before 3ef3d52a1a9860d094395c7a3e593f3aa26ff012	CNA record
linux linux_kernel linux:linux_kernel	from 4.8 before 6.1.162; from 6.2 before 6.6.122; from 6.7 before 6.12.68; from 6.13 before 6.18.8; 6.19; 6.19; 6.19; 6.19; and 2 more ranges	NVD

References

References

https://git.kernel.org/stable/c/d96de882d6b99955604669d962ae14e94b66a551	patch
https://git.kernel.org/stable/c/02f9af192b98d15883c70dd41ac76d1b0217c899	patch
https://git.kernel.org/stable/c/d05bc313788f0684b27f0f5b60c52a844669b542	patch
https://git.kernel.org/stable/c/ec0f1b3da8061be3173d1c39faaf9504f91942c3	patch
https://git.kernel.org/stable/c/3ef3d52a1a9860d094395c7a3e593f3aa26ff012	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.