Log in Start free

Vulnerability · Published Jul 19, 2026 · Assigned by Linux

CVE-2026-64089batman-adv: tt: fix negative last_changeset_len

Critical 9.8

In plain English

A critical-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.6%top 53.7% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

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().

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.176-1DEBIAN-CVE-2026-64089
Debian:13linux6.12.94-1DEBIAN-CVE-2026-64089
Debian:14linux7.0.12-1DEBIAN-CVE-2026-64089
Ubuntu:22.04:LTSlinux5.15.0-186.196UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux6.8.0-139.139USN-8729-1
Ubuntu:24.04:LTSlinux6.8.0-139.139UBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux7.0.0-28.28UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-aws5.15.0-1112.119UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-aws6.8.0-1064.67USN-8729-6
Ubuntu:24.04:LTSlinux-aws6.8.0-1064.67UBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux-aws7.0.0-1009.9UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1064.67~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1064.67~22.04.1USN-8729-6
Ubuntu:22.04:LTSlinux-azure5.15.0-1117.126UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure6.8.0-1067.75USN-8761-1
Ubuntu:24.04:LTSlinux-azure6.8.0-1067.75UBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux-azure7.0.0-1010.10UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1067.75~22.04.1USN-8761-3
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1067.75~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1117.126UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1065.72UBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1009.9UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1065.72~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gcp5.15.0-1112.122UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gcp6.8.0-1067.75UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gcp6.8.0-1067.75USN-8729-1
Ubuntu:26.04:LTSlinux-gcp7.0.0-1008.8UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1067.75~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1067.75~22.04.1USN-8729-3
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gke5.15.0-1108.114UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gke6.8.0-1062.70UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gke6.8.0-1062.70USN-8729-1
Ubuntu:26.04:LTSlinux-gke7.0.0-1003.4UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1095.103UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1049.53USN-8729-1
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1049.53UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-28.28~24.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-ibm5.15.0-1106.110UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-ibm6.8.0-1064.65UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-ibm6.8.0-1064.65USN-8729-3
Ubuntu:26.04:LTSlinux-ibm7.0.0-1010.10UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1066.67~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1107.113UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-kvm5.15.0-1104.109UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-184.194UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-139.139.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-139.139.1USN-8729-4
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-139.139.1~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-139.139.1~22.04.1USN-8729-4
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1107.108UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1062.65UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1062.65USN-8729-1
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1016.16UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1062.65~22.04.1USN-8729-1
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1062.65~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1016.16~24.04.1UBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2016.16UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1062.65.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1062.65.1USN-8729-1
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1064.66UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1035.38UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1053.53UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1009.9UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-oracle5.15.0-1109.115UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oracle6.8.0-1061.64UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oracle6.8.0-1061.64USN-8802-1
Ubuntu:26.04:LTSlinux-oracle7.0.0-1008.8UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1061.64~22.04.1USN-8802-1
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1061.64~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-raspi5.15.0-1106.109UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-raspi6.8.0-1064.68UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-raspi6.8.0-1064.68USN-8729-1
Ubuntu:26.04:LTSlinux-raspi7.0.0-1015.15UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux-realtime7.0.0-28.28.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64089
Ubuntu:26.04:LTSlinux-riscv7.0.0-28.28.1UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-139.139~22.04.1UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-28.28.1~24.04.3UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-64089
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1036.37USN-8729-3
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1036.37UBUNTU-CVE-2026-64089
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1075.79UBUNTU-CVE-2026-64089

Affected products (as reported)

VendorProductVersions
Linux Linux a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before 6314089acf0ddf64376fdc0b1420695504c73f52a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before 55dc41fe8821e9a849e147255ad572bc933a9d15a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before c424e8519ac78eac5d9f4eecf06208a0d619ec14a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before 22d59c72f4a47ffec121d0610f70d0d70c3c11c8a73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before eb235472b52ef36981c5aad330485eaf2382c53ba73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before 179eb62506a02d00370bd6478898cb632e10986ca73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before d29abf70c665730e249d2ec8e1402095ae26bceea73105b8d4c765d9ebfb664d0a66802127d8e4c7 – before fc92cdfcb295cefa4344d71a527d61b638b7bfc4
Linux Linux 3.1

References