CVE-2026-74678 net: usb: ax88179_178a: fix skb leak in ax88179_tx_fixup()
A memory leak in the Linux kernel's ax88179_178a USB network driver can cause resource exhaustion and denial of service under memory pressure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74678?
CVE-2026-74678 is a high-severity denial of service vulnerability in Linux, published on 22 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: usb: ax88179_178a: fix skb leak in ax88179_tx_fixup()
When the interface has NETIF_F_SG enabled and skb_linearize() fails in ax88179_tx_fixup(), the function returns NULL without freeing the skb.
usbnet_start_xmit() treats a NULL return from tx_fixup() as a drop (info->flags does not set FLAG_MULTI_PACKET for this driver), jumping to the "drop" label where it does `if (skb) dev_kfree_skb_any(skb)`. Because tx_fixup() returned NULL, the local skb variable in usbnet_start_xmit() is NULL, so the original skb is never freed — a memory leak on every TX frame whose linearization fails (i.e. under memory pressure).
Free the skb before returning, matching the error handling already used for the pskb_expand_head() failure path in the same function.
Which versions are affected by CVE-2026-74678?
How do I fix CVE-2026-74678?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-74678 being exploited?
There is no known exploitation of CVE-2026-74678 in the wild and no public exploit code.
Sources
Also known as AZL-97359, BELL-CVE-2026-74678, DEBIAN-CVE-2026-74678, GHSA-5prv-rfcq-7r84, UBUNTU-CVE-2026-74678.