CVE-2026-46320: Linux kernel · tap: free page on error paths in tap_get_user_xdp()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.4 High · fixed in f979971835dddbca86cf99e3b2e2b94a408a1ab2 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:30 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 16% 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 f979971835dddbca86cf99e3b2e2b94a408a1ab2, e27c17346628cb56843a83f93ac63c314c00f388, d68eab61944a9b0826fa2e954e42db1aa3201b7a +5
CVSS:3.1/AV:A/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: tap: free page on error paths in tap_get_user_xdp() tap_get_user_xdp() rejects a frame shorter than ETH_HLEN with -EINVAL, and returns -ENOMEM when build_skb() fails. Both paths jump to the err label without freeing the page that vhost_net_build_xdp() allocated for the frame. tap_sendmsg() discards the per-buffer return value and always returns 0, so vhost_tx_batch() takes the success path and never frees the page; each rejected frame in a batch leaks one page-frag chunk. Free the page on both error paths, before the skb is built. This is the tap counterpart of the same leak in tun_xdp_one().
References
- git.kernel.org/stable/c/8d03e65eb6cfbffec471a6b65416f93679bf3286 (opens in a new tab)
- git.kernel.org/stable/c/f979971835dddbca86cf99e3b2e2b94a408a1ab2 (opens in a new tab)
- git.kernel.org/stable/c/3f52a86a482a69294c50a5a2a097bd6f4104990a (opens in a new tab)
- git.kernel.org/stable/c/d30aac0fa00ca0afc3e08174cf7f974a66bdcf05 (opens in a new tab)
- git.kernel.org/stable/c/d68eab61944a9b0826fa2e954e42db1aa3201b7a (opens in a new tab)
- git.kernel.org/stable/c/e27c17346628cb56843a83f93ac63c314c00f388 (opens in a new tab)
- git.kernel.org/stable/c/18a84c35842e19cd3c5534d8cee73d31863f696d (opens in a new tab)
- git.kernel.org/stable/c/3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)