batman-adv: tt: fix negative last_changeset_len
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix negative last_changeset_len batadv_piv_tt::last_changeset_len len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_my_tt_response(), last_changeset_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_local_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_my_tt_response().
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.1 and later | 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 3.1 and later Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.1 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.142; 6.7 to before 6.12.92; 6.13 to before 6.18.34; 6.19 to before 7.0.11 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | 7.1 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | 7.1 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | 7.1 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | 7.1 rc4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.1 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.142; 6.7 to before 6.12.92; 6.13 to before 6.18.34; 6.19 to before 7.0.11 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64089
- 2026-10-03 Alias added: GHSA-7jfx-377j-9v79
- 2026-10-20 Affected versions changed · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/6314089acf0ddf64376fdc0b1420695504c73f52
- https://git.kernel.org/stable/c/55dc41fe8821e9a849e147255ad572bc933a9d15
- https://git.kernel.org/stable/c/c424e8519ac78eac5d9f4eecf06208a0d619ec14
- https://git.kernel.org/stable/c/22d59c72f4a47ffec121d0610f70d0d70c3c11c8
- https://git.kernel.org/stable/c/eb235472b52ef36981c5aad330485eaf2382c53b
- https://git.kernel.org/stable/c/179eb62506a02d00370bd6478898cb632e10986c
- https://git.kernel.org/stable/c/d29abf70c665730e249d2ec8e1402095ae26bcee
- https://git.kernel.org/stable/c/fc92cdfcb295cefa4344d71a527d61b638b7bfc4
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Sources
- CVE-2026-64089 · CVE Program
- CVE-2026-64089 · NVD
- FIRST EPSS
- GHSA-7jfx-377j-9v79 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64089 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences