vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes (CVE-2026-89776) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89776

vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes

Answer in brief

CVE-2026-89776 records a Unknown severity vulnerability in vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 16, 2026Updated Sep 16, 2026Source checked Sep 16, 2026First seen by HOL Sep 16, 2026Material review Sep 16, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <e12c4663529699f457b2988c1dfedf4d13b3b3be \|\| >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <47bfcc871576eaef6c8edab6749acd4b317306ea \|\| >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <a9ec10815199f9879ba080241dc555efb1daf324 \|\| >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <daebc7064a1b4c12c98e52c4bceede7f2fcd573c \|\| >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <ad32e564c62ebf5ba76dd60a22af52c69d54d17b \|\| >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <984f831dda31b3a18f47454cf64989f65402879e	e12c4663529699f457b2988c1dfedf4d13b3b3be, 47bfcc871576eaef6c8edab6749acd4b317306ea, a9ec10815199f9879ba080241dc555efb1daf324, daebc7064a1b4c12c98e52c4bceede7f2fcd573c, ad32e564c62ebf5ba76dd60a22af52c69d54d17b, 984f831dda31b3a18f47454cf64989f65402879e
Linux/Linuxgeneric	5.18	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to e12c4663529699f457b2988c1dfedf4d13b3b3be if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 16, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.