CVE-2025-68734: Linux kernel · isdn: mISDN: hfcsusb: fix memory leak in hfcsusb_probe()
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1103.110~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1103.110~20.04.1, 5.15.0-1110.119~20.04.1, 5.15.0-1103.112~20.04.1 +69
Exploitation evidence
Disclosed: evidence found.
CVE published 24 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
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
An official fix is available and included in Ubuntu security notice USN-8029-1. Users should apply the updated Linux kernel packages for Ubuntu 20.04.1 that include this patch. No additional mitigation is required beyond applying the vendor-provided update.
Description
A memory leak vulnerability in the Linux kernel's ISDN mISDN hfcsusb driver (hfcsusb_probe function) has been fixed. The issue occurs when memory allocated for ctrl_urb is leaked if setup_instance() fails. The fix involves freeing the urb before freeing the hardware structure and revising error handling paths. This vulnerability affects certain Linux kernel versions prior to specific 5.15.0 builds on Ubuntu 20.04.1. The issue was identified using static analysis and has been addressed in official Ubuntu security updates.
References
- ubuntu.com/security/CVE-2025-68734 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68734 (opens in a new tab)
- git.kernel.org/stable/c/03695541b3349bc40bf5d6563d44d6147fb20260 (opens in a new tab)
- git.kernel.org/stable/c/3f7c72bc73c4e542fde14cce017549d8a0b61a3c (opens in a new tab)
- git.kernel.org/stable/c/3f978e3f1570155a1327ffa25f60968bc7b9398f (opens in a new tab)
- git.kernel.org/stable/c/475032fa2bb82ffb592c321885e917e39f47357f (opens in a new tab)
- git.kernel.org/stable/c/6dce43433e0635e7b00346bc937b69ce48ea71bb (opens in a new tab)
- git.kernel.org/stable/c/adb7577e23a431fc53aa1b6107733c0d751015fb (opens in a new tab)
- git.kernel.org/stable/c/b70c24827e11fdc71465f9207e974526fb457bb9 (opens in a new tab)
- git.kernel.org/stable/c/ea7936304ed74ab7f965d17f942a173ce91a5ca8 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8100-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-2 (opens in a new tab)