CVE-2026-64091: linux
Vulnerability summary
CVE-2026-64091 is a critical (CVSS 9.8) vulnerability in linux. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.4% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 30 · Related 30Timeline
- 19-07-2026PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix TOCTOU race for reported vlans The local TT based TVLV is generated by first checking the number of VLANs which have at least one TT entry. A new buffer with the correct size for the VLANs is then allocated. Only then, the list of VLANs s used to fill the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock is held. But the actual number of TT entries of each VLAN can still increase during this time - just not the number of VLANs in the list. But the prefilter used in the buffer size calculation might still cause an increase of the number of VLANs which need to be stored. Simply because a VLAN might now suddenly have at least one entry when it had none in the pre-alloc check - and then needs to occupy space which was not allocated. It is better to overestimate the buffer size at the beginning and then fill the buffer only with the VLANs which are not empty.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.43%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
0.00 pp
From 0.43% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu167 products
- linuxAll versions (No fix recorded) | < 5.15.0-194.204 | < 6.8.0-142.142 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1116.123 | < 6.8.0-1065.68 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 16116dac23396e73c01eeee97b102e4833a4b205, < e4236bf3ec8d6bb15d0d8d825dcf9933a7d6666b | ≥ 16116dac23396e73c01eeee97b102e4833a4b205, < 724a8eb4155669797c96b70d70e354284ae3b5a8 | ≥ 16116dac23396e73c01eeee97b102e4833a4b205, < 211ea59988e1cba43cb0367ad65d379b56f9c3bd | ≥ 16116dac23396e73c01eeee97b102e4833a4b205, < 65a1e67339aa8c95ac544b796946af388930ee23 | ≥ 16116dac23396e73c01eeee97b102e4833a4b205, < b4d4efd4e351593c81e9293d4b4408d244fa5ee7 | ≥ 16116dac23396e73c01eeee97b102e4833a4b205, < 4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227f | ≥ 16116dac23396e73c01eeee97b102e4833a4b205, < 9a9c859457bc440a55773e01ff18b1bb5bab6836 | ≥ 16116dac23396e73c01eeee97b102e4833a4b205, < 94d27005016be15ffc638b2ecbc4d58805ad7b48 | 3134c5a32810c510f1f447c135cec346acbb71c3 | e861e03a1b5b615ad1b57b1802b17e260eedccfe | 0b81edc8818903c64c4d121bc51cd5825be8cc67 | 90ae6475b1753f0c1a4c66034b5666de3189fac8 | ≥ 3.16.60, < 3.17 | ≥ 4.4.217, < 4.5 | ≥ 4.9.217, < 4.10 | ≥ 4.14.174, < 4.15 | 4.17
- linux_kernel≥ 3.16.60, < 3.17 | ≥ 4.4.217, < 4.5 | ≥ 4.9.217, < 4.10 | ≥ 4.14.174, < 4.15 | ≥ 4.17.1, < 5.10.259 | ≥ 5.11, < 5.15.210 | ≥ 5.16, < 6.1.176 | ≥ 6.2, < 6.6.143 | ≥ 6.7, < 6.12.93 | ≥ 6.13, < 6.18.34 | ≥ 6.19, < 7.0.11 | 4.17 | 4.17:rc7 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.12-1
3 vendors · 170 products
