CVE Intelligence
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CVE-2026-98856 — kprobes: Skip disarmed probes when checking optkprobe overlap

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.

Published Oct 18, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • No scoring signals.

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Linux
Linux
CVSS base
—
Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ afd66255b9a48f5851326ddae50e2203fbf71dc9 and < 985a568171e7bdba6dcde3420d0e5bb515813457≥ afd66255b9a48f5851326ddae50e2203fbf71dc9 and < 6745fa65f4115045431c0c15610e876855a04625≥ afd66255b9a48f5851326ddae50e2203fbf71dc9 and < 526fac219e8b7d3369b43026bd0a1df51b811cd4≥ afd66255b9a48f5851326ddae50e2203fbf71dc9 and < 7a39c732a22ec4a369af9e19fbe3d666ec83eec4version 2.6.34 Vulnerable CVE Program (cve.org) e CISA ADP

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Not enough vector or weakness data: use the affected application’s logs as a starting point.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Record published
    Oct 18, 2026
  • Affected products added · linux/linux
    Oct 18, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Received
    Oct 18, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 18, 2026 · NIST National Vulnerability Database
  • CVE published
    Oct 18, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 1× References added · Oct 19, 2026 – Oct 19, 2026
  • 1× Official description updated · Oct 18, 2026 – Oct 18, 2026

References

6 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
  • CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
  • CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
  • CVE-2026-98865 sched_ext: Don't run ops.dequeue() with a DSQ lock held 1d
  • CVE-2026-98864 sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task 1d
  • CVE-2026-98863 KVM: x86: Re-pend GET_NESTED_STATE_PAGES if getting said pages fails 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No CVSS score published by NVD, the CNA, CISA or GitHub so far.
  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No CWE classification.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-98856 is "kprobes: Skip disarmed probes when checking optkprobe overlap", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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