CVE-2026-23069: Linux kernel · vsock/virtio: fix potential underflow in virtio_transport_get_credit()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1057.60~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- 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.
- Patch
- Available – fixed in 6.8.0-1057.60~22.04.1, 6.8.0-1059.65~22.04.1, 6.8.0-1060.63~22.04.1 +27
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation 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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available from the vendor. Users should update their linux-azure kernel packages to versions 6.8.0-1055.56~22.04.1 or later as provided in the Ubuntu security advisories USN-8278-1 and USN-8289-1. After applying the update, a system reboot is required. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be necessary. Follow the vendor's update instructions carefully to ensure full remediation.
Description
A vulnerability in the Linux kernel's vsock/virtio subsystem could cause an unsigned arithmetic underflow in the function virtio_transport_get_credit(). This underflow may allow the system to queue more data than the peer can handle. The issue has been fixed by reusing the virtio_transport_has_space() function, which properly handles this case. The vulnerability affects multiple linux-azure kernel versions prior to 6.8.0-1055.56~22.04.1 and related builds. A patch is available and should be applied to mitigate the risk. The CVSS score is 5.5 (medium severity) with impact limited to availability (denial of service).
References
- ubuntu.com/security/CVE-2026-23069 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23069 (opens in a new tab)
- git.kernel.org/linus/3ef3d52a1a9860d094395c7a3e593f3aa26ff012 (opens in a new tab)
- git.kernel.org/stable/c/02f9af192b98d15883c70dd41ac76d1b0217c899 (opens in a new tab)
- git.kernel.org/stable/c/3ef3d52a1a9860d094395c7a3e593f3aa26ff012 (opens in a new tab)
- git.kernel.org/stable/c/d05bc313788f0684b27f0f5b60c52a844669b542 (opens in a new tab)
- git.kernel.org/stable/c/ec0f1b3da8061be3173d1c39faaf9504f91942c3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8393-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8440-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8570-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8604-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8605-1 (opens in a new tab)