VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98742: Linux kernel · ALSA: seq: Serialize compat port-info ioctls

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in fc5c52848e405b6efb073db5035bb9ebaed11ec4 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in fc5c52848e405b6efb073db5035bb9ebaed11ec4, 413211dd31cb2ef2fc99fb0aa1a037a97509502c, 702d92f361f65d9698c473c7599d471395dc4341 +9

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 >=3.2.99 <3.3 >=3.16.54 <3.17 >=3.18.94 <3.19 >=4.1.50 <4.2 >=4.4.115 <4.5 >=4.9.78 <4.10 >=4.14.15 <4.15	Fixed in fc5c52848e405b6efb073db5035bb9ebaed11ec4 413211dd31cb2ef2fc99fb0aa1a037a97509502c 702d92f361f65d9698c473c7599d471395dc4341 95b2e0361c88753afa030c10698be0a1a5b67650 4.15 4.10 4.5 4.2 3.19 3.17 3.3 2db234e163f0d211b69a4eebbec8aacc5a54a80e
LinuxLinux	Affected =4.15	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Serialize compat port-info ioctls The native sequencer ioctl path serializes handler calls with client->ioctl_mutex, but the translated port-info compat path invokes the same handlers through snd_seq_kernel_client_ctl() without taking that mutex. This lets concurrent compat CREATE_PORT requests pass the port-count check before any request reaches the serialized insertion. The computed integer port index can then exceed the address field range and wrap to an existing index. Subsequent subscriber teardown can resolve the duplicate address to the wrong port and access a freed subscriber. Take ioctl_mutex while dispatching converted port-info requests, matching the native ioctl path. All translated port-info commands share this helper, so their accesses to the client port state are serialized as well.

References

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