VulnerabilityPublished 18 Oct 2026

CVE-2026-98826: Linux kernel · rtc: ac100: Fix clock provider use-after-free on probe failure

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in fcf0b58e976e83adf246b014518e49c662b96f5e : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · 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 fcf0b58e976e83adf246b014518e49c662b96f5e, 55ca60ba336632349f7c4585d22ba74ae355b7ce, 12bcd20d76703ee2baf52224d287b7fea096b12f +1

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.

What to do

Upgrade Linux kernel to fcf0b58e976e83adf246b014518e49c662b96f5e, 55ca60ba336632349f7c4585d22ba74ae355b7ce, 12bcd20d76703ee2baf52224d287b7fea096b12f or 9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ d00a18a42c1483924de086ddfb0efe8da1dba3ac, < fcf0b58e976e83adf246b014518e49c662b96f5e	Fixed in fcf0b58e976e83adf246b014518e49c662b96f5e
LinuxLinux	Affected ≥ d00a18a42c1483924de086ddfb0efe8da1dba3ac, < 55ca60ba336632349f7c4585d22ba74ae355b7ce	Fixed in 55ca60ba336632349f7c4585d22ba74ae355b7ce
LinuxLinux	Affected ≥ d00a18a42c1483924de086ddfb0efe8da1dba3ac, < 12bcd20d76703ee2baf52224d287b7fea096b12f	Fixed in 12bcd20d76703ee2baf52224d287b7fea096b12f
LinuxLinux	Affected ≥ d00a18a42c1483924de086ddfb0efe8da1dba3ac, < 9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8	Fixed in 9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8
LinuxLinux	Affected =4.9	Fixed in–

AI-suggested

A fix is available and has been applied in the Linux kernel commits identified by hashes fcf0b58e976e83adf246b014518e49c662b96f5e, 55ca60ba336632349f7c4585d22ba74ae355b7ce, 12bcd20d76703ee2baf52224d287b7fea096b12f, and 9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8. Users should update to a kernel version including these fixes. No additional mitigations are necessary as the patch ensures proper resource management on probe failure.

Description

A use-after-free vulnerability in the Linux kernel's rtc ac100 driver was fixed. The issue occurs when the probe function fails after registering clocks that are not device-managed, leaving dangling pointers in the global clock provider list. This can lead to use of freed memory and resource leaks, causing later probe failures for the same device. The fix ensures proper device-managed registration and cleanup on probe failure.

Impact

Use-after-free conditions can cause kernel memory corruption and instability. The dangling clock provider pointer can lead to invalid memory reads in the kernel, potentially causing crashes or undefined behavior. The resource leak also causes subsequent device probe failures, impacting device functionality. However, exploitation requires a narrow failure window and specific conditions. There are no known exploits in the wild.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 09:43 UTC

Technical details

References

Community reviews

Related threats