High

CVE-2026-64552 — virtio-net: fix len check in receive_big()

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.

Published Jul 27, 2026 · Updated Oct 15, 2026 · Sources: CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.1% (30-day exploitation probability)+0
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.14%

ahead of 3% of scored CVEs · Oct 14, 2026

Affects

Linux

CVSS base

8.4

High · 3 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 82f9028e83944a9eee5229cbc6fee9be1de8a62d and < f9451d0fd5ba635dcabb49bfe456a6db734a8986≥ 946dec89c41726b94d31147ec528b96af0be1b5a and < 38e94d63e29f4a5c6eae87ee2c02101aaa321502≥ 82fe78065450d2d07f36a22e2b6b44955cf5ca5b and < fbeb65154583879d556ea94cb2f15888e9470f3d≥ 0c716703965ffc5ef4311b65cb5d84a703784717 and < c7fc9adf4e006155f7f2aeda052fbcde25cdcc49≥ 0c716703965ffc5ef4311b65cb5d84a703784717 and < e6b8463b7d791f3886d7584259d6e9f06a69f12e≥ 0c716703965ffc5ef4311b65cb5d84a703784717 and < 9e5ad06ea826322ce8c58b4a68442a96f600c3c4version 3e9d89f2ecd3636bd4cbdfd0b2dfdaf58f9882e2≥ 6.1.159 and < 6.1.178 and 4 more ≥ 6.6.117 and < 6.6.145≥ 6.12.58 and < 6.12.97≥ 6.17.8 and < 6.18version 6.18	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.4	CVSS 3.1	High	2.5	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.4	CVSS 3.1	High	—	—	GitHub, Inc. via GitHub Security Advisories
8.4	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Source status changed · Published → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record published
Oct 15, 2026
CVSS changed · 8.4
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Published
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record created in this database
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
CVE published
Jul 27, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 15, 2026 – Oct 15, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

10 on the record

git.kernel.org/stable/c/f9451d0fd5ba635dcabb49bfe456a6db734a8986
CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/fbeb65154583879d556ea94cb2f15888e9470f3d
CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/c7fc9adf4e006155f7f2aeda052fbcde25cdcc49
CVE Program (cve.org) e CISA ADP
github.com/advisories/GHSA-6c34-77j2-7g8c
GitHub Security Advisories
git.kernel.org/stable/c/38e94d63e29f4a5c6eae87ee2c02101aaa321502
CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/e6b8463b7d791f3886d7584259d6e9f06a69f12e
CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/9e5ad06ea826322ce8c58b4a68442a96f600c3c4
CVE Program (cve.org) e CISA ADP
cert-portal.siemens.com/productcert/html/ssa-457936.html
NIST National Vulnerability Database
cert-portal.siemens.com/productcert/html/ssa-019113.html
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-64552
GitHub Security Advisories

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 12h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 12h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-64552 is "virtio-net: fix len check in receive_big()", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.4 describes technical severity. EPSS 0.14% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.