CVE-2025-40071: Linux kernel · tty: n_gsm: Don't block input queue by waiting MSC
Source GCVE Database
Not known to be exploited · fixed in c36785f9de03df56ff9b8eca30fa681a12b2310d : update Linux kernel when convenient.
Data as of 30 Oct 2026, 16:33 UTC
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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| 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
- nvd.nist.gov/vuln/detail/CVE-2025-40071 (opens in a new tab)
- git.kernel.org/stable/c/3cf0b3c243e56bc43be560617416c1d9f301f44c (opens in a new tab)
- git.kernel.org/stable/c/5416e89b81b00443cb03c88df8da097ae091a141 (opens in a new tab)
- git.kernel.org/stable/c/8fcc22d6b90304d8b7436e101562218ea3faf73b (opens in a new tab)
- git.kernel.org/stable/c/c36785f9de03df56ff9b8eca30fa681a12b2310d (opens in a new tab)
- git.kernel.org/stable/c/c5a2791a7f11939f05f95c01f0aec0c55bbf28d5 (opens in a new tab)