CVE-2026-43020: linux Out-of-bounds Write
Vulnerability summary
CVE-2026-43020 is a high (CVSS 7.8) Out-of-bounds Write vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 47 · Related 39Timeline
- 01-05-2026PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate LTK enc_size on load Load Long Term Keys stores the user-provided enc_size and later uses it to size fixed-size stack operations when replying to LE LTK requests. An enc_size larger than the 16-byte key buffer can therefore overflow the reply stack buffer. Reject oversized enc_size values while validating the management LTK record so invalid keys never reach the stored key state.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.13%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
0.00 pp
From 0.13% 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
Ubuntu157 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < 0f37d1e65c6d71ad94ccfb5c602163c525db789d | ≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < 257cdb960d8ff6d60bb6461b03c814b6cf0c9e64 | ≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < c34577f517b556fb6ca173d45bf7e766ae2564ce | ≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < f71695e81f4cb428f3c7e2138eae88199005b52c | ≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < 82f342b3b006ca1d65f4890c05f2ec32fcb808b6 | ≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < 50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257 | ≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < 40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009 | ≥ 346af67b8d116f01ef696fd47959a55deb2db8b6, < b8dbe9648d69059cfe3a28917bfbf7e61efd7f15 | 3.4
- linux_kernel≥ 3.4, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.168 | ≥ 6.2, < 6.6.134 | ≥ 6.7, < 6.12.81 | ≥ 6.13, < 6.18.22 | ≥ 6.19, < 6.19.12 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6
Debian1 product
- linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.12-1
3 vendors · 160 products
