VulnerabilityPublished 4 Feb 2026Updated 19 Oct 2026

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

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in ec0f1b3da8061be3173d1c39faaf9504f91942c3 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 10:24 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS

0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-06-10.

Patch

Available – fixed in ec0f1b3da8061be3173d1c39faaf9504f91942c3, d96de882d6b99955604669d962ae14e94b66a551, d05bc313788f0684b27f0f5b60c52a844669b542 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 06a8fc78367d070720af960dcecec917d3ae5f3b, < ec0f1b3da8061be3173d1c39faaf9504f91942c3	Fixed in ec0f1b3da8061be3173d1c39faaf9504f91942c3
LinuxLinux	Affected ≥ 06a8fc78367d070720af960dcecec917d3ae5f3b, < d96de882d6b99955604669d962ae14e94b66a551	Fixed in d96de882d6b99955604669d962ae14e94b66a551
LinuxLinux	Affected ≥ 06a8fc78367d070720af960dcecec917d3ae5f3b, < d05bc313788f0684b27f0f5b60c52a844669b542	Fixed in d05bc313788f0684b27f0f5b60c52a844669b542
LinuxLinux	Affected ≥ 06a8fc78367d070720af960dcecec917d3ae5f3b, < 3ef3d52a1a9860d094395c7a3e593f3aa26ff012	Fixed in 3ef3d52a1a9860d094395c7a3e593f3aa26ff012
LinuxLinux	Affected ≥ 06a8fc78367d070720af960dcecec917d3ae5f3b, < 02f9af192b98d15883c70dd41ac76d1b0217c899	Fixed in 02f9af192b98d15883c70dd41ac76d1b0217c899
LinuxLinux	Affected =4.8	Fixed in–

Description

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]

CWE-190Integer Overflow or Wraparound (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
Requirements
Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.3 (opens in a new tab)
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-190

Technical details

References

Community reviews

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