CVE-2026-31778: Linux kernel · ALSA: caiaq: fix stack out-of-bounds read in init_card
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in a82c1bce2d1299dd3c686a8fe48cf75b79a403c7 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:33 UTC
Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in a82c1bce2d1299dd3c686a8fe48cf75b79a403c7, 66194c2575a4f567577ae70b1d7561163ce791a6, 45424e871abf2a152e247a9cff78359f18dd95c0 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 1 May 2026
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 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in multiple Linux kernel commits. Users and administrators should update their Linux kernel to a version that includes the fix (commits such as a82c1bce2d1299dd3c686a8fe48cf75b79a403c7 and others). No additional mitigation steps are indicated or required beyond applying the official patch.
Description
A stack out-of-bounds read vulnerability exists in the ALSA caiaq driver in the Linux kernel due to improper handling of string termination in the init_card function. The issue arises from a loop that copies a card shortname without reserving space for a null terminator, leading to reading beyond the stack buffer. This flaw has been present since Linux kernel version 2.6.31-rc1 (June 2009) and is triggered by USB devices with product names containing many non-ASCII, non-space characters. The vulnerability has been fixed by adjusting the loop boundary to ensure proper null termination.
References
- git.kernel.org/stable/c/02d9c5b0b5553a391448b6d655262bd829f90234 (opens in a new tab)
- git.kernel.org/stable/c/3f7f8bae0d52cbd07ab04b76b6aac89ef98ee9f6 (opens in a new tab)
- git.kernel.org/stable/c/66194c2575a4f567577ae70b1d7561163ce791a6 (opens in a new tab)
- git.kernel.org/stable/c/a82c1bce2d1299dd3c686a8fe48cf75b79a403c7 (opens in a new tab)
- git.kernel.org/stable/c/3178b62e2e31bab39f63d4c8e54bf4ee0a425627 (opens in a new tab)
- git.kernel.org/stable/c/3afa2e67f3523a980a2f90fd63c22322ac2b9ce0 (opens in a new tab)
- git.kernel.org/stable/c/7594a6464873d90fd229e5b94cdd3b92c9feabed (opens in a new tab)
- git.kernel.org/stable/c/45424e871abf2a152e247a9cff78359f18dd95c0 (opens in a new tab)