Service interruption via unaligned ARP address reads
Published Sep 16, 2026 · Updated Sep 16, 2026
Unaligned access in Linux batman-adv allows attackers to trigger a fault during ARP processing on alignment-sensitive hardware. The batadv_arp_ip_src and batadv_arp_ip_dst paths directly read IPv4 addresses from potentially unaligned SKB data instead of using get_unaligned(). Reachability requires Distributed ARP Table processing on hardware without native unaligned-read support.
Summary
What happened
Unaligned access in Linux batman-adv allows attackers to trigger a fault during ARP processing on alignment-sensitive hardware. The batadv_arp_ip_src and batadv_arp_ip_dst paths directly read IPv4 addresses from potentially unaligned SKB data instead of using get_unaligned(). Reachability requires Distributed ARP Table processing on hardware without native unaligned-read support.
The record
- CVE
- CVE-2026-89949
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- adjacent
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.8
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <0121afa52cdb88cfb4d5d7bd126a23a9100121d8
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <0c2df865338bbf92aa45b9253e5f9b8ef2d9992f
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <15dbfb37f0e1a085d48deeb8f5238e9d28127dde
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <1cfa7d5f70d54cb8c7e82df739430782d1996ee1
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <91c99b4e152023c7d458a5dedd52d2b0d7df4ce3
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <a170d4617e8cca05a1314de61728a262ef272782
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <b1bbc694ca51adb8dbed3f3235b4fcbdb44e0e20
- Affected versionversion=5c3a0e5535933349a5d6e6bc8b704e0611f21d3f <c74a4acf41d19f21199dec2d6c813c90d31cd02c
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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