CVE-2026-90139: Linux kernel · fuse: check for NULL root inode in fuse_fill_super_submount
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1 : update Linux kernel when convenient.
Data as of 30 Oct 2026, 12:51 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1, a5129155ca9fba40d77ff19ffead8244e88d6f9c, 17120c5bfb16808509ea18d7fab6027802d93eba +3
Exploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available in the Linux kernel as indicated by the fixed commit versions. Users should update to a kernel version including these fixes to prevent the null pointer dereference. No additional mitigation is required once patched.
Description
A null pointer dereference vulnerability exists in the Linux kernel's FUSE subsystem in the fuse_fill_super_submount function. This occurs because fuse_iget() can return NULL on inode allocation failure, but fuse_fill_super_submount() does not check for NULL before using the inode, leading to a kernel crash (oops). The issue is triggered under memory pressure conditions. The vulnerability has been fixed by returning an error code instead of dereferencing NULL.
References
- git.kernel.org/stable/c/4844aeb0de5fb0de4f7c9aaf2bf05cb8cffe60d5 (opens in a new tab)
- git.kernel.org/stable/c/17120c5bfb16808509ea18d7fab6027802d93eba (opens in a new tab)
- git.kernel.org/stable/c/e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1 (opens in a new tab)
- git.kernel.org/stable/c/a5129155ca9fba40d77ff19ffead8244e88d6f9c (opens in a new tab)
- git.kernel.org/stable/c/509f4a09bae7f03c87f67f053648874a5e177867 (opens in a new tab)
- git.kernel.org/stable/c/928f659a3e3650978a5b4829cc982324f72b474b (opens in a new tab)