CVE-2025-68734 isdn: mISDN: hfcsusb: fix memory leak in hfcsusb_probe()
A memory leak in the Linux kernel's hfcsusb ISDN driver allows local attackers to cause denial of service by exhausting system memory.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68734?
CVE-2025-68734 is a memory corruption vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
isdn: mISDN: hfcsusb: fix memory leak in hfcsusb_probe()
In hfcsusb_probe(), the memory allocated for ctrl_urb gets leaked when setup_instance() fails with an error code. Fix that by freeing the urb before freeing the hw structure. Also change the error paths to use the goto ladder style.
Compile tested only. Issue found using a prototype static analysis tool.
Which versions are affected by CVE-2025-68734?
How do I fix CVE-2025-68734?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-68734 being exploited?
There is no known exploitation of CVE-2025-68734 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68734, DEBIAN-CVE-2025-68734, GHSA-m755-w853-wg37, ROOT-OS-UBUNTU-2204-CVE-2025-68734, ROOT-OS-UBUNTU-2404-CVE-2025-68734, UBUNTU-CVE-2025-68734.