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NVD / CVE Program· CNA Linux

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

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.17% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 02f9af192b98d15883c70dd41ac76d1b0217c899, 3ef3d52a1a9860d094395c7a3e593f3aa26ff012, d05bc313788f0684b27f0f5b60c52a844669b542; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 02f9af192b98d15883c70dd41ac76d1b0217c899, 3ef3d52a1a9860d094395c7a3e593f3aa26ff012, d05bc313788f0684b27f0f5b60c52a844669b542; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes 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: 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]

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 4, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 7th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-23069

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.8 and later · before 6.1.162
  • linux linux kernel6.2 and later · before 6.6.122
  • linux linux kernel6.7 and later · before 6.12.68
  • linux linux kernel6.13 and later · before 6.18.8
  • linux linux kernel6.19

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

    • 4.8affected
    • 06a8fc78367d070720af960dcecec917d3ae5f3b and later · before d96de882d6b99955604669d962ae14e94b66a551affected · git
    • 06a8fc78367d070720af960dcecec917d3ae5f3b and later · before 02f9af192b98d15883c70dd41ac76d1b0217c899affected · git
    • 06a8fc78367d070720af960dcecec917d3ae5f3b and later · before d05bc313788f0684b27f0f5b60c52a844669b542affected · git
    • 06a8fc78367d070720af960dcecec917d3ae5f3b and later · before ec0f1b3da8061be3173d1c39faaf9504f91942c3affected · git
    • 06a8fc78367d070720af960dcecec917d3ae5f3b and later · before 3ef3d52a1a9860d094395c7a3e593f3aa26ff012affected · git
    • before 4.8not affected · semver
    • 6.1.162 and later · up to and including 6.1.*not affected · semver
    • 6.6.122 and later · up to and including 6.6.*not affected · semver
    • 6.12.68 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.162-16.1.162-1
Debian:13linuxbefore 6.12.69-16.12.69-1
Debian:14linuxbefore 6.18.8-16.18.8-1
SUSE:Linux Micro 6.1kernel-defaultbefore 6.4.0-41.16.4.0-41.1
SUSE:Linux Micro 6.1kernel-default-basebefore 6.4.0-41.1.21.186.4.0-41.1.21.18
SUSE:Linux Micro 6.1kernel-kvmsmallbefore 6.4.0-41.16.4.0-41.1
SUSE:Linux Micro 6.1kernel-rtbefore 6.4.0-41.16.4.0-41.1
SUSE:Linux Micro 6.1kernel-sourcebefore 6.4.0-41.16.4.0-41.1
SUSE:Linux Micro 6.1kernel-source-rtbefore 6.4.0-41.16.4.0-41.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-23066Feb 4, 2026 · rxrpc: Fix recvmsg() unconditional requeue
    22Monitor
  • ← EarlierCVE-2026-23067Feb 4, 2026 · iommu/io-pgtable-arm: fix size_t signedness bug in unmap path
    22Monitor
  • Later →CVE-2026-23070Feb 4, 2026 · Octeontx2-af: Add proper checks for fwdata
    22Monitor

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 Linux02f9af192b98d15883c70dd41ac76d1b0217c899Vendor (CNA)
Linux Linux3ef3d52a1a9860d094395c7a3e593f3aa26ff012Vendor (CNA)
Linux Linuxd05bc313788f0684b27f0f5b60c52a844669b542Vendor (CNA)
Linux Linuxd96de882d6b99955604669d962ae14e94b66a551Vendor (CNA)
Linux Linuxec0f1b3da8061be3173d1c39faaf9504f91942c3Vendor (CNA)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.1.162-1 · Debian:12Package registry (OSV)
suse:kernel-default6.4.0-41.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-default-base6.4.0-41.1.21.18 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-kvmsmall6.4.0-41.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-rt6.4.0-41.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-source6.4.0-41.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-source-rt6.4.0-41.1 · SUSE:Linux Micro 6.1Package 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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-53176141 days apartIB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN
    39Monitor
  • CVE-2026-63940165 days apartKVM: SEV: Ignore Port I/O requests of length '0'
    37Monitor
  • CVE-2026-4318791 days apartxfs: delete attr leaf freemap entries when empty
    35Monitor
  • CVE-2026-53178141 days apartstaging: rtl8723bs: rtw_mlme: add bounds checks before ie_length subtraction
    32Monitor
  • CVE-2026-3165679 days apartdrm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat
    31Monitor
  • CVE-2026-46107113 days apartdm-thin: fix metadata refcount underflow
    31Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-191 · Integer Underflow (Wrap or Wraparound)

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

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.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

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

All records