CVE-2026-72310: Linux kernel · smb: client: fix overflow in passthrough ioctl bounds check
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +42
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 for the affected linux-hwe-edge kernel versions. Users should apply the official kernel updates provided by their vendor to remediate this vulnerability. No additional mitigation steps are indicated beyond applying the patch.
Description
A vulnerability in the Linux kernel SMB client was fixed that involved an integer overflow in the bounds check of the passthrough ioctl response payload. The flaw allowed a malicious SMB server to craft a response that bypassed bounds checking, potentially causing out-of-bounds reads in kernel memory. This issue affects specific versions of the linux-hwe-edge kernel and has a high severity rating with a CVSS score of 8.1. A patch is available to correct the bounds check by properly handling integer overflow.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72310 (opens in a new tab)
- git.kernel.org/stable/c/160045fc943f6c46b227644261252c8a22b8a87a (opens in a new tab)
- git.kernel.org/stable/c/1627e7d5c9b09721a141d07cedb178882f1ded67 (opens in a new tab)
- git.kernel.org/stable/c/175357ee0c596cb82054650dfa32fda51ad35aaa (opens in a new tab)
- git.kernel.org/stable/c/1a638c55f2db6cb2296e5e3138015dd8fd9d4aa9 (opens in a new tab)
- git.kernel.org/stable/c/63feb687e89a3a52a31e6e01764117cc500f1974 (opens in a new tab)
- git.kernel.org/stable/c/a4f27ad055392fa164f5649e89a3637b033c5fcc (opens in a new tab)
- git.kernel.org/stable/c/b30771b69eafae750afb7385fbcc3d77ed3f3670 (opens in a new tab)
- git.kernel.org/stable/c/dbd126539c098dba3159ce7d34b10b2daddcbd0f (opens in a new tab)
- ubuntu.com/security/CVE-2026-72310 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72310 (opens in a new tab)
- git.kernel.org/linus/a4f27ad055392fa164f5649e89a3637b033c5fcc (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)