VulnerabilityPublished 18 Oct 2026

CVE-2026-98530: Linux kernel · kprobes: Fix permanent hang when flushing the kprobe optimizer

Source GCVE Database

Authoritative record:CVE-2026-98530· High

Not known to be exploited : upgrade to f05a01fc7d4f731b4c100d2aef1e85ad77728862 or 5bfa9f1a9dcb6ecb607adbc1c0226605c972935b soon.

Data as of 26 Oct 2026, 14:05 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% 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 f05a01fc7d4f731b4c100d2aef1e85ad77728862, 5bfa9f1a9dcb6ecb607adbc1c0226605c972935b

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-2p4m-w3h2-4q6g

What to do

Upgrade Linux kernel to f05a01fc7d4f731b4c100d2aef1e85ad77728862 or 5bfa9f1a9dcb6ecb607adbc1c0226605c972935b.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 73c12f209462d1712c5f55f3021a1b65b2e084c3, < f05a01fc7d4f731b4c100d2aef1e85ad77728862	Fixed in f05a01fc7d4f731b4c100d2aef1e85ad77728862
LinuxLinux	Affected ≥ 73c12f209462d1712c5f55f3021a1b65b2e084c3, < 5bfa9f1a9dcb6ecb607adbc1c0226605c972935b	Fixed in 5bfa9f1a9dcb6ecb607adbc1c0226605c972935b
LinuxLinux	Affected =7.0	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to replace the completion mechanism with a counter and proper synchronization to prevent the hang. Users should apply the official kernel update that includes this fix. Since this is a kernel-level issue, upgrading to a patched kernel version is the recommended remediation. No alternative workarounds are indicated.

Description

A vulnerability in the Linux kernel's kprobes subsystem caused a permanent hang when flushing the kprobe optimizer. Writing 0 to /proc/sys/debug/kprobes-optimization while a kprobe is jump-optimized results in the writer process sleeping indefinitely with a mutex held, causing subsequent reads or writes to hang. The issue stems from improper synchronization and completion handling in the optimizer flushing logic, leading to deadlock conditions.

References

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