High

CVE-2026-46321 — tun: free page on short-frame rejection in tun_xdp_one()

In the Linux kernel, the following vulnerability has been resolved: tun: free page on short-frame rejection in tun_xdp_one() tun_xdp_one() returns -EINVAL on a frame shorter than ETH_HLEN without freeing the page that vhost_net_build_xdp() allocated for it. tun_sendmsg() discards that -EINVAL and still returns total_len, so vhost_tx_batch() takes the success path and never frees the page; each short frame in a batch leaks one page-frag chunk. A local process that can open /dev/net/tun and /dev/vhost-net can hit this path: it attaches a tun/tap device as the vhost-net backend and feeds TX descriptors whose length minus the virtio-net header is below ETH_HLEN. Each kick leaks the page-frag chunks for that batch, and a tight submission loop exhausts host memory and triggers an OOM panic. Free the page before returning -EINVAL, matching the XDP-program error path in the same function.

Published Jun 9, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, 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

0.13%

ahead of 2% of scored CVEs · Oct 14, 2026

Affects

Linux

Linux and 1 more

CVSS base

7.1

High · 3 source(s)

Remediation

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

Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)

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, Linux Linux Kernel).
Apply the fixed version or the patch documented under Remediation.
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	≥ 5.10.223 and < 5.10.259≥ d5ad89b7d01ed4e66fd04734fc63d6e78536692a and < 5b34f9e4fe2f203724a6e893d6df0316b9670057≥ 049584807f1d797fc3078b68035450a9769eb5c3 and < 69863ff2720a0e9871f1a5710f2a33a94217fee0≥ 049584807f1d797fc3078b68035450a9769eb5c3 and < 37a1c268c2c8090bf4dc552d732bd23ba36f8eb0≥ 049584807f1d797fc3078b68035450a9769eb5c3 and < 98c67be9eb9de72465a071949e84a3cdb8fab5a3≥ 049584807f1d797fc3078b68035450a9769eb5c3 and < f4feb1e20058e407cb00f45aff47f5b7e19a6bbfversion 32b0aaba5dbc85816898167d9b5d45a22eae82e9version a9d1c27e2ee3b0ea5d40c105d6e728fc114470bb and 11 more version 8418f55302fa1d2eeb73e16e345167e545c598a5≥ ad6b3f622ccfb4bfedfa53b6ebd91c3d1d04f146 and < e915445942af6dcea628bf66d6241641201a0c41≥ 5.15.164 and < 5.15.210≥ 6.1.102 and < 6.1.176≥ 6.6.43 and < 6.6.143≥ 5.4.281 and < 5.5≥ 6.9.12 and < 6.10≥ 6.10.2 and < 6.11version 6.11≥ 589382f50b4a5d90d16d8bc9dcbc0e927a3e39b2 and < 0e8211fcf9426f5adddf32516ba0f400ceb9544d≥ 6100e0237204890269e3f934acfc50d35fd6f319 and < 0a6f46a9332ad6958992d64d3b3a81a80b2ca940	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	≥ 5.4.281 and < 5.5version 7.1-rc5version 7.1-rc4version 7.1-rc3version 7.1-rc2version 7.1-rc1≥ 6.19 and < 7.0.12≥ 6.13 and < 6.18.35 and 6 more ≥ 6.10.2 and < 6.12.93≥ 6.9.12 and < 6.10≥ 6.6.43 and < 6.6.143≥ 6.1.102 and < 6.1.176≥ 5.15.164 and < 5.15.210≥ 5.10.223 and < 5.10.259	Vulnerable	NIST National Vulnerability Database

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

Changed

Confidentiality

None

Integrity

None

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
7.1	CVSS 3.1	High	2.5	4.0	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.1	CVSS 3.1	High	—	—	GitHub, Inc. via GitHub Security Advisories
7.1	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:C/C:N/I:N/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.19%

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 · Analyzed → Modified
Oct 14, 2026 · NIST National Vulnerability Database
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 7.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 9, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 14, 2026 – Oct 15, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

11 on the record

git.kernel.org/stable/c/e915445942af6dcea628bf66d6241641201a0c41
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/69863ff2720a0e9871f1a5710f2a33a94217fee0
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/0e8211fcf9426f5adddf32516ba0f400ceb9544d
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/37a1c268c2c8090bf4dc552d732bd23ba36f8eb0
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/0a6f46a9332ad6958992d64d3b3a81a80b2ca940
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/5b34f9e4fe2f203724a6e893d6df0316b9670057
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/98c67be9eb9de72465a071949e84a3cdb8fab5a3
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/f4feb1e20058e407cb00f45aff47f5b7e19a6bbf
Patch, NIST National Vulnerability Database
github.com/advisories/GHSA-3qqh-vm6g-ghw6
GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2026-46321
GitHub Security Advisories
cert-portal.siemens.com/productcert/html/ssa-784472.html
NIST National Vulnerability Database

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 6h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 6h
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 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-2026-46321 is "tun: free page on short-frame rejection in tun_xdp_one()", 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 7.1 describes technical severity. EPSS 0.13% 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.

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