CVE-2026-98992: Linux kernel · namespace: don't copy an unmounted mount tree
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in b47b40c4f058418f9707454543179df240796aad : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:18 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in b47b40c4f058418f9707454543179df240796aad, 86a2d56b1960720bf1844441c0890621e9db2f25, 8d3527457e183cedee3003c2897314da49488311 +2
Exploitation evidence
Disclosed: evidence found.
CVE published 23 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
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– |
AI-suggested
A fix is available and has been applied in the Linux kernel. The fix refuses to recursively copy unmounted mount trees, causing such operations to fail with EINVAL. Users should update to a Linux kernel version that includes the fix identified by the commits b47b40c4f058418f9707454543179df240796aad, 86a2d56b1960720bf1844441c0890621e9db2f25, 8d3527457e183cedee3003c2897314da49488311, 8bacbf6be959973b28b691713a872c12eae69eec, or 7e037b1fd339d865737c8accd29abcf40130a5a0.
Description
A vulnerability in the Linux kernel's namespace handling allows recursive copying of an unmounted mount tree, which should not be allowed. This occurs because the function may_copy_tree() improperly permits copying of mounts that are lazily unmounted but still held alive by file descriptors, leading to unintended copying of the entire unmounted stack. The issue has been fixed by refusing to walk unmounted trees recursively, causing such operations to fail with EINVAL.
References
- git.kernel.org/stable/c/86a2d56b1960720bf1844441c0890621e9db2f25 (opens in a new tab)
- git.kernel.org/stable/c/7e037b1fd339d865737c8accd29abcf40130a5a0 (opens in a new tab)
- git.kernel.org/stable/c/b47b40c4f058418f9707454543179df240796aad (opens in a new tab)
- git.kernel.org/stable/c/8d3527457e183cedee3003c2897314da49488311 (opens in a new tab)
- git.kernel.org/stable/c/8bacbf6be959973b28b691713a872c12eae69eec (opens in a new tab)