Kernel memory disclosure and corruption via signed length
Published Jul 19, 2026 · Updated Jul 19, 2026
Integer overflow in the Linux kernel batman-adv subsystem allows remote attackers to disclose or corrupt kernel memory via mesh traffic. A value above 32767 wraps the signed batadv_piv_tt::last_changeset_len field negative; sign extension then drives an oversized memcpy while batadv_tt_prepare_tvlv_local_data() leaves much of its response buffer uninitialized. Exploitation requires a known mesh originator, a high-MTU node with more than 2730 TT changes, and a crafted TT_REQUEST, enabling kernel-data disclosure, heap corruption, or a kernel panic.
Summary
What happened
Integer overflow in the Linux kernel batman-adv subsystem allows remote attackers to disclose or corrupt kernel memory via mesh traffic. A value above 32767 wraps the signed batadv_piv_tt::last_changeset_len field negative; sign extension then drives an oversized memcpy while batadv_tt_prepare_tvlv_local_data() leaves much of its response buffer uninitialized. Exploitation requires a known mesh originator, a high-MTU node with more than 2730 TT changes, and a crafted TT_REQUEST, enabling kernel-data disclosure, heap corruption, or a kernel panic.
The record
- CVE
- CVE-2026-64089
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1210
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 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=3.1
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <179eb62506a02d00370bd6478898cb632e10986c
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <22d59c72f4a47ffec121d0610f70d0d70c3c11c8
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <55dc41fe8821e9a849e147255ad572bc933a9d15
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <6314089acf0ddf64376fdc0b1420695504c73f52
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <c424e8519ac78eac5d9f4eecf06208a0d619ec14
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <d29abf70c665730e249d2ec8e1402095ae26bcee
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <eb235472b52ef36981c5aad330485eaf2382c53b
- Affected versionversion=a73105b8d4c765d9ebfb664d0a66802127d8e4c7 <fc92cdfcb295cefa4344d71a527d61b638b7bfc4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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