CVE-2025-39765: Linux kernel · ALSA: timer: fix ida_free call while not allocated
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in af386b52531d14c4b20f11c452787b1b6dd4eb8d : update Linux kernel when convenient.
Data as of 5 Nov 2026, 21:36 UTC
Rated Low 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, 2026-11-05.
- Patch
- Available – fixed in af386b52531d14c4b20f11c452787b1b6dd4eb8d, 34327b362ce2849a5eb02f47e800049e7a20a0ba, 5003a65790ed66be882d1987cc2ca86af0de3db1
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 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 5 Nov 2026.
What to do
Upgrade Linux kernel to af386b52531d14c4b20f11c452787b1b6dd4eb8d, 34327b362ce2849a5eb02f47e800049e7a20a0ba or 5003a65790ed66be882d1987cc2ca86af0de3db1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available in the Linux kernel as indicated by the fixed commit versions. Users should update to a kernel version that includes the fix identified by commits af386b52531d14c4b20f11c452787b1b6dd4eb8d, 34327b362ce2849a5eb02f47e800049e7a20a0ba, or 5003a65790ed66be882d1987cc2ca86af0de3db1. No additional mitigation steps are necessary.
Description
A flaw in the Linux kernel ALSA timer subsystem was fixed where an improper call to ida_free() could occur on an unallocated ID 0. This happened if kasprintf() returned NULL during snd_utimer_create(), leading to snd_utimer_put_id() freeing an ID that was never allocated.