CVE-2026-98388: Linux kernel · exec: do_close_on_exec() before taking exec_update_lock
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 23:28 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 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
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.
Description
In the Linux kernel, the following vulnerability has been resolved: exec: do_close_on_exec() before taking exec_update_lock do_close_on_exec() currently happens while holding the exec_update_lock, which is used in a lot of places that access process state to synchronize access checks. I recently added another such use of exec_update_lock, causing a regression. do_close_on_exec() can block waiting for a reply from a filesystem. That means a hung filesystem can block codepaths that use exec_update_lock; and it also means that a FUSE filesystem which attempts to inspect the calling process can deadlock. To avoid such problems, move do_close_on_exec() before the exec_update_lock is taken, but after the FD table has been copied if necessary. I have looked through all the calls between the old and new position of the do_close_on_exec() call; there seems to be no file descriptor table access in between.
References
- ubuntu.com/security/CVE-2026-98388 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98388 (opens in a new tab)
- git.kernel.org/stable/c/5aacc19ba2b1faf84c4a2f2cf9a1784e03d1ff38 (opens in a new tab)
- git.kernel.org/stable/c/550feab5b01000ab314868b62211fb3ddfd600e8 (opens in a new tab)
- git.kernel.org/stable/c/e780259b54e618ceb4763fbc21314acf3565e813 (opens in a new tab)
- git.kernel.org/stable/c/3feb4020bfb7ccf0d347f27051639d25e19cd65d (opens in a new tab)
- git.kernel.org/stable/c/0d86cd6b709c39216e6ee5ea8f0fc4242bbb2b53 (opens in a new tab)
- git.kernel.org/stable/c/63be3d8511bdafa095cd14a393cbf3c58dbbb928 (opens in a new tab)
- git.kernel.org/stable/c/19ddef61ee0a49782a60f8f497e50597ad5de2da (opens in a new tab)
- git.kernel.org/stable/c/955973fff4a36d39a848b00cac1706863f568fe1 (opens in a new tab)