CVE-2026-64552
CVE-2026-64552 is a security vulnerability. O3 Security confirms whether CVE-2026-64552 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: virtio-net: fix len check in receive_big() receive_big() bounds the device-announced length by (big_packets_num_skbfrags…
Description
In the Linux kernel, the following vulnerability has been resolved:
virtio-net: fix len check in receive_big()
receive_big() bounds the device-announced length by (big_packets_num_skbfrags + 1) * PAGE_SIZE. That is still too loose: add_recvbuf_big() sets sg[1] to start at offset sizeof(struct padded_vnet_hdr) into the first page, so the chain actually carries hdr_len + (PAGE_SIZE - sizeof(padded_vnet_hdr)) + big_packets_num_skbfrags * PAGE_SIZE bytes -- 20 bytes less than the check allows for the common hdr_len == 12 case.
A malicious virtio backend can announce a len in that gap. page_to_skb() then walks one frag past the page chain, storing a NULL page->private into skb_shinfo()->frags[MAX_SKB_FRAGS], which is both an out-of-bounds write past the static frag array and a NULL frag handed up the rx path.
Bound len by the size add_recvbuf_big() actually advertised.
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-2026-64552 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-2026-64552 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-2026-64552. 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-2026-64552 in your dependencies?
O3 detects CVE-2026-64552 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.