CVE-2026-89776
In the Linux kernel, the following vulnerability has been resolved: vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes The VXLAN VNI filter entry policy declares the GROUP/GROUP6 address attributes as NLA_BINARY with only a maximum length, so validate_nla() accepts a payload shorter than the address. The GROUP consumer reads it with nla_get_in_addr(), an unconditional 4-byte load, so a short attribute over-reads up to 3 bytes of uninitialised slab data, which are stored into remote_ip and echoed back via RTM_GETTUNNEL, disclosing kernel memory. Switch both entries to NLA_POLICY_EXACT_LEN() so the validator rejects any GROUP/GROUP6 that is not exactly 4 / 16 bytes; a valid address is always sent at full width.
Affected versions
Linux kernel versions
5.18
and later are affected. Fixed in
6.1.188,
6.6.157,
6.12.110,
6.18.52,
7.2.6,
7.3-rc1
and their respective stable series.
References
6 totalFrequently asked questions
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What is CVE-2026-89776?
CVE-2026-89776 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.18 onward and has been patched in 6.1.188, 6.6.157, 6.12.110 and others. CVE-2026-89776 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-89776?
Yes. CVE-2026-89776 has been patched. Fixed versions include 6.1.188, 6.6.157, 6.12.110 and others. If you are running Linux kernel 5.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-89776 actively exploited?
No. CVE-2026-89776 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.