VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98856: Linux kernel · kprobes: Skip disarmed probes when checking optkprobe overlap

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 6745fa65f4115045431c0c15610e876855a04625 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · 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 6745fa65f4115045431c0c15610e876855a04625, 985a568171e7bdba6dcde3420d0e5bb515813457, 526fac219e8b7d3369b43026bd0a1df51b811cd4 +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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ afd66255b9a48f5851326ddae50e2203fbf71dc9, < 6745fa65f4115045431c0c15610e876855a04625	Fixed in 6745fa65f4115045431c0c15610e876855a04625
LinuxLinux	Affected ≥ afd66255b9a48f5851326ddae50e2203fbf71dc9, < 985a568171e7bdba6dcde3420d0e5bb515813457	Fixed in 985a568171e7bdba6dcde3420d0e5bb515813457
LinuxLinux	Affected ≥ afd66255b9a48f5851326ddae50e2203fbf71dc9, < 526fac219e8b7d3369b43026bd0a1df51b811cd4	Fixed in 526fac219e8b7d3369b43026bd0a1df51b811cd4
LinuxLinux	Affected ≥ afd66255b9a48f5851326ddae50e2203fbf71dc9, < 7a39c732a22ec4a369af9e19fbe3d666ec83eec4	Fixed in 7a39c732a22ec4a369af9e19fbe3d666ec83eec4
LinuxLinux	Affected ≥ afd66255b9a48f5851326ddae50e2203fbf71dc9, < 3f968dcdf018861129f97910fa7bd680d939a9b0	Fixed in 3f968dcdf018861129f97910fa7bd680d939a9b0
LinuxLinux	Affected =2.6.34	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: kprobes: Skip disarmed probes when checking optkprobe overlap On x86, an optkprobe at A replaces five bytes with a jump. If a disabled probe B is at A+2, get_optimized_kprobe() stops at B when arming a new probe C at A+4. It leaves A optimized: A A+1 A+2 A+3 A+4 A's jump | e9 | d0 | d1 | d2 | d3 | after C | e9 | d0 | d1 | d2 | cc | The INT3 for C overwrites the last byte of A's jump displacement, so execution can jump to the wrong address. B can have prepared optinsns while disarmed, but has no jump to unoptimize. Continue past disarmed and unprepared probes to find the active optimized probe before arming a probe in its jump.

References

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