CVE-2025-40269: Linux kernel · ALSA: usb-audio: Fix potential overflow of PCM transfer buffer
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 7 Dec 2025
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.
What to do
AI-suggested
A patch has been introduced to the Linux kernel that adds a sanity check to prevent buffer overflow by validating packet sizes against the maximum USB descriptor size and returning an error if exceeded. Users should apply the official Linux kernel updates that include this fix. Since this is a kernel-level vulnerability, updating to the patched kernel version is the recommended remediation. Patch status is not explicitly stated here; check the official Linux kernel advisories for the exact fixed versions and apply updates accordingly.
Description
A vulnerability in the Linux kernel's ALSA usb-audio driver could cause a buffer overflow due to improper validation of PCM transfer packet sizes. The driver calculates packet sizes based on rate and packets per second, which may exceed the USB descriptor's maximum packet size, leading to overflow. A patch has been introduced to add a sanity check that returns an error if the packet size exceeds the allowed maximum, preventing the overflow.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40269 (opens in a new tab)
- git.kernel.org/stable/c/05a1fc5efdd8560f34a3af39c9cf1e1526cc3ddf (opens in a new tab)
- git.kernel.org/stable/c/217d47255a2ec8b246f2725f5db9ac3f1d4109d7 (opens in a new tab)
- git.kernel.org/stable/c/282aba56713bbc58155716b55ca7222b2d9cf3c8 (opens in a new tab)
- git.kernel.org/stable/c/480a1490c595a242f27493a4544b3efb21b29f6a (opens in a new tab)
- git.kernel.org/stable/c/6a5da3fa80affc948923f20a4e086177f505e86e (opens in a new tab)
- git.kernel.org/stable/c/98e9d5e33bda8db875cc1a4fe99c192658e45ab6 (opens in a new tab)
- git.kernel.org/stable/c/ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41 (opens in a new tab)
- git.kernel.org/stable/c/c4dc012b027c9eb101583011089dea14d744e314 (opens in a new tab)
- git.kernel.org/stable/c/d2c04f20ccc6c0d219e6d3038bab45bc66a178ad (opens in a new tab)
- git.kernel.org/stable/c/d67dde02049e632ba58d3c44a164a74b6a737154 (opens in a new tab)
- git.kernel.org/stable/c/e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360 (opens in a new tab)
- git.kernel.org/stable/c/ece3b981bb6620e47fac826a2156c090b1a936a0 (opens in a new tab)
- git.kernel.org/stable/c/ef592bf2232a2daa9fffa8881881fc9957ea56e9 (opens in a new tab)