Affects the Linux kernel (core OS widely deployed). Kernel-level faults can disrupt large numbers of servers/containers and gain broad attention.
CVE-2026-74427
Linux kernel AFS netns teardown bug can cause kernel memory corruption and crashes.
Is CVE-2026-74427 being exploited?
Not confirmed. CVE-2026-74427 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 0.40% probability of exploitation in the next 30 days.
How severe is CVE-2026-74427?
CVE-2026-74427 is rated Critical with a CVSS score of 9.8. 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-2026-74427?
Yes. A fix has been recorded for CVE-2026-74427. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74427 affect?
CVE-2026-74427 affects Linux kernel (AFS subsystem, rxrpc). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74427?
Apply vendor kernel updates and reboot affected hosts immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local attacker or container can trigger netns teardown race, causing use-after-free -> kernel crash or potential local privilege escalation.
Immediate action required
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < 63ccaf1bdf8be2330f47f9b5b233dd3fd04acbd9
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < f5096e18b6b7fbd1c2a1942e275a51bcfdfb2ad1
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < 59e8b7652f6cbfb62d377ead0ad553c1b4e39a7a
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < 85d5fb80fe4f0cc836b6df83f26de204fe102ff7
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < a33975ff2b6ea47b8f29956403374b1cdd057539
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < b83ecf80e28afb7b6595ba79932e77ca68a5a83d
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < eec89c5f8e1adc1de4824042ef75f62aed804153
- affected>= 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and < 47694fbc9d24ab6bf210f91e8efe06a10a478064
- affected4.9
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.