CVE-2026-74539
Linux kernel Bluetooth ISO locking bug can cause kernel memory corruption or crash.
Is CVE-2026-74539 being exploited?
Not confirmed. CVE-2026-74539 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-74539?
CVE-2026-74539 is rated High with a CVSS score of 8.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-74539?
Yes. A fix has been recorded for CVE-2026-74539. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74539 affect?
CVE-2026-74539 affects Linux kernel (Bluetooth ISO subsystem), Linux distributions using affected kernel versions, Bluetooth-enabled Linux hosts. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74539?
Install vendor/kernel updates and restrict Bluetooth access until patched
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote Bluetooth interaction or local socket calls can trigger a race leading to kernel memory corruption, crashes (DoS), or possible local privilege escalation.
Patch when possible
- affected>= 2df108c227b266a9ec9e3fda3828d2ac9662aa33 and < 72d5bb1d77d7c3330146dc0cfd43f704c64b9594
- affected>= 2df108c227b266a9ec9e3fda3828d2ac9662aa33 and < 202670e6602e068558c1fca2df40719ee91a2906
- affected>= 2df108c227b266a9ec9e3fda3828d2ac9662aa33 and < 89cf154d7c18e6e94a3da83051f3cf2bac317ae2
- affected6.16
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.