CVE-2026-100081: Linux kernel · xen-netback: defer xenvif_mcast_addr_list_free()
Source GCVE Database
Not known to be exploited · fixed in fb38fc58acb26d74fe8f7b19621fafaae3c040ff : update Linux kernel when convenient.
Data as of 6 Nov 2026, 22:48 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in fb38fc58acb26d74fe8f7b19621fafaae3c040ff, a6bb2f1fa62c56279bdcdadce28d1310c5e12b62, 990d123d9eaa3ac6c979eed245658676d65ce0db +4
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 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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Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability has been implemented by deferring the xenvif_mcast_addr_list_free() call to after the synchronization point in backend_disconnect(). Users should apply the official Linux kernel updates that include this fix. No additional mitigation actions are indicated.
Description
CVE-2026-100081 is a vulnerability in the Linux kernel's xen-netback component related to the improper timing of the xenvif_mcast_addr_list_free() function call. The fix involves deferring this function call to occur after all transmit and receive processing has stopped, ensuring proper synchronization and avoiding locking or RCU issues. This vulnerability is tracked as XSA-527.
References
- nvd.nist.gov/vuln/detail/CVE-2026-100081 (opens in a new tab)
- git.kernel.org/stable/c/0d515c409033c8e2a645a781be3ca76ab825fc8c (opens in a new tab)
- git.kernel.org/stable/c/0e786123e46d08d2247ce93a5435e45ed9f4c5d1 (opens in a new tab)
- git.kernel.org/stable/c/34f0f63dc6dc11895a17bb5672451b6b11622c99 (opens in a new tab)
- git.kernel.org/stable/c/96e05a8ce243e2207704e2e7a6e7d1172730f515 (opens in a new tab)
- git.kernel.org/stable/c/990d123d9eaa3ac6c979eed245658676d65ce0db (opens in a new tab)
- git.kernel.org/stable/c/a6bb2f1fa62c56279bdcdadce28d1310c5e12b62 (opens in a new tab)
- git.kernel.org/stable/c/fb38fc58acb26d74fe8f7b19621fafaae3c040ff (opens in a new tab)
- openwall.com/lists/oss-security/2026/11/06/10 (opens in a new tab)
- xenbits.xen.org/xsa/advisory-527.html (opens in a new tab)