VulnerabilityPublished 18 Oct 2026

CVE-2026-98505: Linux kernel · mm/damon/vaddr: avoid hw-driven pte updates during damon_hugetlb_mkold()

Source GCVE Database

Authoritative record:CVE-2026-98505

Not known to be exploited · fixed in e59cb7eda7c06334a0faf5aa44adb6acf2a1287a : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in e59cb7eda7c06334a0faf5aa44adb6acf2a1287a, 00457981327c80bcc56e07d4714fe189337a19fa, 39c0ceedd54557bdc1542de08d22b2ed33e534e4 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-mr9h-5fpp-c352

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 49f4203aae06ba9d67b500c90339b262b0a52637, < e59cb7eda7c06334a0faf5aa44adb6acf2a1287a	Fixed in e59cb7eda7c06334a0faf5aa44adb6acf2a1287a
LinuxLinux	Affected ≥ 49f4203aae06ba9d67b500c90339b262b0a52637, < 00457981327c80bcc56e07d4714fe189337a19fa	Fixed in 00457981327c80bcc56e07d4714fe189337a19fa
LinuxLinux	Affected ≥ 49f4203aae06ba9d67b500c90339b262b0a52637, < 39c0ceedd54557bdc1542de08d22b2ed33e534e4	Fixed in 39c0ceedd54557bdc1542de08d22b2ed33e534e4
LinuxLinux	Affected ≥ 49f4203aae06ba9d67b500c90339b262b0a52637, < 7ed1062d154ec2401f2c894fd6858598bb1160b6	Fixed in 7ed1062d154ec2401f2c894fd6858598bb1160b6
LinuxLinux	Affected ≥ 49f4203aae06ba9d67b500c90339b262b0a52637, < 6e74ffc9ecf6ec24eee117150da78a1102be74c5	Fixed in 6e74ffc9ecf6ec24eee117150da78a1102be74c5
LinuxLinux	Affected =5.17	Fixed in–

AI-suggested

A fix is available in the Linux kernel that addresses the race condition by atomically clearing the page table entry during read operations using huge_ptep_get_and_clear(). Users should update to the fixed Linux kernel version containing this patch. No additional mitigation is indicated by the vendor advisory.

Description

A vulnerability in the Linux kernel's memory management subsystem related to huge page table entry (PTE) updates has been resolved. The issue involves the damon_hugetlb_mkold() function, which updates page table entries without properly handling concurrent hardware-driven updates, potentially causing loss of hardware-updated bits such as dirty bits. The fix avoids parallel updates by clearing the page table entry atomically during read operations. Since hugetlbfs is an in-memory filesystem and huge pages cannot be reclaimed, no critical impact is expected. The vulnerability was discovered by Sashiko and has been addressed in the Linux kernel.

Impact

The vulnerability could cause loss of hardware-driven updates to page table entries, such as dirty bits, due to race conditions during concurrent updates by the kernel and hardware. However, since the affected subsystem deals with huge pages in an in-memory filesystem (hugetlbfs) where pages cannot be reclaimed, the impact is not considered critical or leading to system instability or data loss under normal conditions.

Summary

The vulnerability in the Linux kernel affects the damon_hugetlb_mkold() function within the mm/damon/vaddr subsystem. This function reads a page table entry (PTE), unsets the accessed bit, and writes back the updated PTE. However, if hardware concurrently updates the same PTE (e.g., setting dirty bits), those hardware updates can be lost due to a race condition. The fix involves using huge_ptep_get_and_clear() to atomically clear the PTE when reading it, ensuring that any concurrent hardware updates trigger a page fault and are properly serialized with the kernel's update. Because hugetlbfs is an in-memory filesystem and huge pages are not reclaimable, the impact is limited. The issue was discovered by Sashiko and has been fixed in the Linux kernel.

References

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