CVE-2026-46322: Linux kernel · tun: free page on build_skb failure in tun_xdp_one()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.1 High · fixed in d16e38fac09a47bfcf98c1ad65a1bb53f94540f5 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% 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
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in d16e38fac09a47bfcf98c1ad65a1bb53f94540f5, aa8963fdce667a42fb7f0bdd2909fadcab02f9a8, aa308e9dbb9acb17cacdbbce9e4504f69bac8385 +5
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: tun: free page on build_skb failure in tun_xdp_one() When build_skb() fails in tun_xdp_one(), the function sets ret to -ENOMEM and jumps to the out label, which returns without freeing the page that vhost_net_build_xdp() allocated for the frame. As with the short-frame rejection path, tun_sendmsg() discards the per-buffer error and still returns total_len, so vhost_tx_batch() takes the success path and never frees the page. Each build_skb() failure in a batch leaks one page-frag chunk. Free the page before taking the error path, matching the put_page() the other error exits of tun_xdp_one() already perform.
References
- git.kernel.org/stable/c/26fe549b5192536b6c1c68a2dfdc8c0dcf9fa4a9 (opens in a new tab)
- git.kernel.org/stable/c/793385c154771603b8671dd8338927221e9d8d78 (opens in a new tab)
- git.kernel.org/stable/c/2638a9c1521905bb5c5d1e95c8fbc09f79148ed7 (opens in a new tab)
- git.kernel.org/stable/c/60d9c0d6cdde5420d6483c921b16fe5465eb5238 (opens in a new tab)
- git.kernel.org/stable/c/d16e38fac09a47bfcf98c1ad65a1bb53f94540f5 (opens in a new tab)
- git.kernel.org/stable/c/aa308e9dbb9acb17cacdbbce9e4504f69bac8385 (opens in a new tab)
- git.kernel.org/stable/c/4fefc6156a162a9f50035c12091a5e5130c82c6e (opens in a new tab)
- git.kernel.org/stable/c/aa8963fdce667a42fb7f0bdd2909fadcab02f9a8 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)