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

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]

Published: 2026-02-04 Last update: 2026-03-13 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23069 is rated Low Risk (23.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23069

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-05 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23069

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-23069

OS Trackers for CVE-2026-23069

vendor priority summary link
debian not yet assigned CVE-2026-23069 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5, open 1. https://security-tracker.debian.org/tracker/CVE-2026-23069
redhat medium — https://access.redhat.com/security/cve/CVE-2026-23069
suse medium CVE-2026-23069 severity moderate: SUSE including 408 source package names (2.1.3-6.144:kernel-default-base-6.4.0-41.1.21.18, 2.1.3-7.127:kernel-default-6.4.0-41.1, …), 594 product×package rows across 38 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (38 product lines)): Fixed 325, Known Affected 231, First Fixed 25, Known Not Affected 13. https://www.suse.com/security/cve/CVE-2026-23069/
ubuntu medium CVE-2026-23069 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1256 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): DNE 871, ignored 170, needed 119, released 83, not-affected 8, pending 5. https://ubuntu.com/security/CVE-2026-23069

Affected software / configurations for CVE-2026-23069

Vendor Product Version Raw CPE
linux linux_kernel >= 4.8, < 6.1.162 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.122 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.68 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.18.8 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*

References for CVE-2026-23069

cvelogic Threat Intelligence