CVE-2026-43019: Bluetooth: hci_conn: fix potential UAF in set_cig_params_sync
Vulnerability summary
CVE-2026-43019 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.8% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 27 · Related 26Timeline
- 01-05-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: fix potential UAF in set_cig_params_sync hci_conn lookup and field access must be covered by hdev lock in set_cig_params_sync, otherwise it's possible it is freed concurrently. Take hdev lock to prevent hci_conn from being deleted or modified concurrently. Just RCU lock is not suitable here, as we also want to avoid "tearing" in the configuration.
CVSS metrics
5 scores · 4 sources · 2 versions- 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
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.10%
Chance of exploitation in the next 30 days
Percentile
1%
Versus all other CVEs
30-day change
Decrease -0.07 pp
From 0.18% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-362Concurrent Execution using Shared Resource with Improper SynchronizationThe product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu130 products
- linux< 6.8.0-136.136 | All versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1061.64 | All versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ a091289218202bc09d9b9caa8afcde1018584aec, < 7502c1cf303b69f71d085f5ff7251b0e1b0f09df | ≥ a091289218202bc09d9b9caa8afcde1018584aec, < 66d432e9b45bae7881ffcdb12cd8fd0bf254ef02 | ≥ a091289218202bc09d9b9caa8afcde1018584aec, < 7d568fede8eac91161a60b710aa920abe9b0fb9f | ≥ a091289218202bc09d9b9caa8afcde1018584aec, < bad65b4b0a96139f023eadc28a33125963208449 | ≥ a091289218202bc09d9b9caa8afcde1018584aec, < a2639a7f0f5bf7d73f337f8f077c19415c62ed2c | 3a273cd0f47dd672d37736e623849374f9ab9ce9 | d8570c4c3f2a3e51b3c8b5e6ec898364c5c03062 | ≥ 6.4.16, < 6.5 | ≥ 6.5.3, < 6.6 | 6.6
- linux_kernelEOL≥ 6.6, < 6.12.81 | ≥ 6.13, < 6.18.22 | ≥ 6.19, < 6.19.12 | 6.4.16 | 6.5.3 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6
Debian1 product
- linux< 6.12.85-1 | < 6.19.12-1
3 vendors · 133 products
