CVE-2026-72393
CVE-2026-72393 is a security vulnerability. O3 Security confirms whether CVE-2026-72393 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: don't cache shinfo across skb realloc fbnic_tx_lso() calls skb_cow_head() which may reallocate the…
Description
In the Linux kernel, the following vulnerability has been resolved:
eth: fbnic: don't cache shinfo across skb realloc
fbnic_tx_lso() calls skb_cow_head() which may reallocate the skb including the shared info. We can't use the pointer calculated before the call.
BUG: KASAN: slab-use-after-free in fbnic_tx_lso.isra.0+0x668/0x8e0
Read of size 4 at addr ff110000262edd98 by task swapper/5/0
Call Trace:
fbnic_tx_lso.isra.0+0x668/0x8e0
fbnic_xmit_frame+0x622/0xba0
dev_hard_start_xmit+0xf4/0x620
Allocated by task 8653:
__alloc_skb+0x11e/0x5f0
alloc_skb_with_frags+0xcc/0x6c0
sock_alloc_send_pskb+0x327/0x3f0
__ip_append_data+0x188b/0x47a0
ip_make_skb+0x24a/0x300
udp_sendmsg+0x14d2/0x21e0
Freed by task 0:
kfree+0x123/0x5a0
pskb_expand_head+0x36c/0xfa0
fbnic_tx_lso.isra.0+0x500/0x8e0
fbnic_xmit_frame+0x622/0xba0
dev_hard_start_xmit+0xf4/0x620
sch_direct_xmit+0x25b/0x1100
The buggy address belongs to the object at ff110000262edc40
which belongs to the cache skbuff_small_head of size 640
The buggy address is located 344 bytes inside of
freed 640-byte region [ff110000262edc40, ff110000262ede
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-72393 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-72393 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-72393. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-72393 in your dependencies?
O3 detects CVE-2026-72393 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.