VulnerabilityPublished 28 Oct 2025Updated 30 Oct 2026

CVE-2025-40071: Linux kernel · tty: n_gsm: Don't block input queue by waiting MSC

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in c36785f9de03df56ff9b8eca30fa681a12b2310d : update Linux kernel when convenient.

Data as of 30 Oct 2026, 12:49 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Patch: Available – fixed in c36785f9de03df56ff9b8eca30fa681a12b2310d, c5a2791a7f11939f05f95c01f0aec0c55bbf28d5, 5416e89b81b00443cb03c88df8da097ae091a141 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 >=5.15.54 <5.16 >=5.17.6 <5.18	Fixed in c36785f9de03df56ff9b8eca30fa681a12b2310d c5a2791a7f11939f05f95c01f0aec0c55bbf28d5 5416e89b81b00443cb03c88df8da097ae091a141 8fcc22d6b90304d8b7436e101562218ea3faf73b 5.18 5.16 3cf0b3c243e56bc43be560617416c1d9f301f44c
LinuxLinux	Affected =5.18	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: Don't block input queue by waiting MSC Currently gsm_queue() processes incoming frames and when opening a DLC channel it calls gsm_dlci_open() which calls gsm_modem_update(). If basic mode is used it calls gsm_modem_upd_via_msc() and it cannot block the input queue by waiting the response to come into the same input queue. Instead allow sending Modem Status Command without waiting for remote end to respond. Define a new function gsm_modem_send_initial_msc() for this purpose. As MSC is only valid for basic encoding, it does not do anything for advanced or when convergence layer type 2 is used.

References

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