CVE-2025-37891: Linux kernel · ALSA: ump: Fix buffer overflow at UMP SysEx message conversion
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-1046.49~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 16:39 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1046.49~22.04.1, 6.8.0-1051.57~22.04.1, 6.8.0-1046.53~22.04.1 +32
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 19 May 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
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7649-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7650-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7649-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7665-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7665-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7721-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-5 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: ump: Fix buffer overflow at UMP SysEx message conversion The conversion function from MIDI 1.0 to UMP packet contains an internal buffer to keep the incoming MIDI bytes, and its size is 4, as it was supposed to be the max size for a MIDI1 UMP packet data. However, the implementation overlooked that SysEx is handled in a different format, and it can be up to 6 bytes, as found in do_convert_to_ump(). It leads eventually to a buffer overflow, and may corrupt the memory when a longer SysEx message is received. The fix is simply to extend the buffer size to 6 to fit with the SysEx UMP message.
References
- ubuntu.com/security/CVE-2025-37891 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37891 (opens in a new tab)
- git.kernel.org/linus/56f1f30e6795b890463d9b20b11e576adf5a2f77 (opens in a new tab)
- git.kernel.org/stable/c/226beac5605afbb33f8782148d188b64396145a4 (opens in a new tab)
- git.kernel.org/stable/c/42ef48dd4ebb082a1a90b5c3feeda2e68a9e32fe (opens in a new tab)
- git.kernel.org/stable/c/56f1f30e6795b890463d9b20b11e576adf5a2f77 (opens in a new tab)
- git.kernel.org/stable/c/ce4f77bef276e7d2eb7ab03a5d08bcbaa40710ec (opens in a new tab)
- ubuntu.com/security/notices/USN-7649-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7650-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7649-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7665-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7665-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7721-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-2 (opens in a new tab)