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VulnerabilityPublished Updated

CVE-2026-64552: Linux kernel · virtio-net: fix len check in receive_big()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.4 High · fixed in fbeb65154583879d556ea94cb2f15888e9470f3d : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
8.4High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in fbeb65154583879d556ea94cb2f15888e9470f3d, f9451d0fd5ba635dcabb49bfe456a6db734a8986, e6b8463b7d791f3886d7584259d6e9f06a69f12e +7
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • >=6.1.159 <6.1.178
  • >=6.6.117 <6.6.145
  • >=6.12.58 <6.12.97
  • >=6.17.8 <6.18
Fixed in
  • fbeb65154583879d556ea94cb2f15888e9470f3d
  • f9451d0fd5ba635dcabb49bfe456a6db734a8986
  • e6b8463b7d791f3886d7584259d6e9f06a69f12e
  • c7fc9adf4e006155f7f2aeda052fbcde25cdcc49
  • 38e94d63e29f4a5c6eae87ee2c02101aaa321502
  • 9e5ad06ea826322ce8c58b4a68442a96f600c3c4
  • 6.18
  • 6.12.97
  • 6.6.145
  • 6.1.178
LinuxLinuxAffected
  • =6.18
Fixed in–

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.

References

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