CVE-2026-98939: Linux kernel · x86/mm: Drop unnecessary PMD page copy when freeing
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in f38c57a28ebbd057471573e39555d5aa11ab03cf : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:30 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 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in f38c57a28ebbd057471573e39555d5aa11ab03cf, e3ee38c1bc0b11a8d3e63dce7050759b61864286, d3c2d2692bdf4af94bb27bc7a3aa0a348a567606 +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 Linux to f38c57a28ebbd057471573e39555d5aa11ab03cf, e3ee38c1bc0b11a8d3e63dce7050759b61864286 or d3c2d2692bdf4af94bb27bc7a3aa0a348a567606; Linux to 7.2.10 or 6.18.56.
Affected software
| Product | 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 Linux kernel versions 6.18.56 and 7.2.10 and later. Users and administrators should upgrade to these or later versions to resolve the issue. No additional mitigation steps are required as the patch removes the problematic allocation and locking dependency.
Description
CVE-2026-98939 is a Linux kernel vulnerability involving unnecessary PMD page copying during page freeing on x86 architectures. This flaw could cause a possible deadlock due to circular locking dependencies when the TTM page pool shrinks on systems with discrete GPUs. The issue arises from holding a mmap_read_lock during kernel page protection operations combined with GFP_KERNEL allocations in page table free paths. The fix removes the PMD copy, detaches the PMD page at the PUD level, flushes mid-level caches, and frees PTE tables directly, eliminating the problematic allocation and locking cycle.