Is there a patch available for EUVD-2026-103801?

Yes, a patch is available for EUVD-2026-103801. Update the affected software to the latest version immediately.

Linux EUVD-2026-103801

| CVE-2026-98861

2026-10-18 Linux

GHSA-7564-v46w-3pmr

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Awaiting Data No severity or threat signals available yet. Label will update when CVSS score is published or threat intelligence arrives. Why: No CVSS yet + weak signal (CWE or non-zero EPSS).

Patch available 0.2% exploitation probability (EPSS)

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AnalysisCVE.org

In the Linux kernel, the following vulnerability has been resolved:

fprobe: Use guard(rcu_sched_notrace) and check rcu_is_watching()

unregister_fprobe() and unregister_fprobe_async() (used by BPF kprobe-multi) rely on standard RCU grace periods (synchronize_rcu() and call_rcu()) to wait until in-flight fprobe handlers complete before freeing the fprobe.

However, if an fprobe handler executes while RCU is not watching (such as in the idle loop or nohz_full extended quiescent states), standard RCU does not track preemption-disabled sections. Consequently, synchronize_rcu() does not wait for those executions, which can lead to a use-after-free if the fprobe is freed immediately after unregistration. Ensure handlers exit early when !rcu_is_watching().

Furthermore, fprobe_fgraph_entry() and fprobe_ftrace_entry() previously used guard(rcu)() and rcu_read_lock(), which invoke lockdep on every hit under CONFIG_PROVE_LOCKING. This adds overhead and can cause lockdep recursion if probed functions interact with lockdep.

Since rhltable_lookup() and rhl_for_each_entry_rcu() use rcu_dereference_all_check() (which checks rcu_read_lock_any_held()), holding preemption disabled via rcu_read_lock_sched_notrace() is fully valid and sufficient so long as rcu_is_watching() is true.

Define and use guard(rcu_sched_notrace)() across fprobe_ftrace_entry(), fprobe_fgraph_entry(), and fprobe_return(). This eliminates fast-path rcu_read_lock() and lockdep overhead while guaranteeing safe grace period synchronization.

Affected VersionsENISA

Linux 56b4cfcf1518245493c60fd39c56978f508f1816 <a85d0f00671b4d4527317c10ba018680f7d8d673

Linux 6.18.34 <6.18.56

Linux patch: 7.2.10

Linux 657b594b2084b39a4bc6d8493aa2140cb00cea49 <e0a6249190402a28f1e2925a81acf573157d55ef

Linux 7.1

Linux a4f6a9005ed6cfd360ef2520430927f05f92ffb0

Linux patch: 0

Linux patch: 6.18.56

Linux patch: 7.3-rc6

Linux 7.0.11 <7.1

Linux 657b594b2084b39a4bc6d8493aa2140cb00cea49 <dd4a0d4993633b45470abf6da4ea0ca563402245

Affected Packages

euvd linux fix: 6.18.56, 7.1

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

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Exploit and PoC references, threat intelligence from 22 sources

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Lifecycle Timeline

Patch available

Oct 18, 2026 - 17:19 EUVD

CVE Published

Oct 18, 2026 - 15:51 cve.org

UNKNOWN (no severity yet)

Threat Intelligence Overview

EPSS Score

0.2%

Top 94% exploitable

Data Quality

1 sources

Confidence: Low

EUVD

CVE.org

EPSS

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity Not scored yet

CISA KEV No

Public POC No

EPSS 0.2%

Patch available Yes

Active threat No

Deciding rule

No CVSS yet + weak signal (CWE or non-zero EPSS)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.