CVE-2026-43249
Linux kernel 9p/xen double-free crash via xenwatch race.
Is CVE-2026-43249 being exploited?
Not confirmed. CVE-2026-43249 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 0.24% probability of exploitation in the next 30 days.
How severe is CVE-2026-43249?
CVE-2026-43249 is rated High with a CVSS score of 8.8. 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-2026-43249?
Yes. A fix has been recorded for CVE-2026-43249. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43249 affect?
CVE-2026-43249 affects Linux kernel (Xen 9pfs frontend). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43249?
Update to patched kernel with Xen 9pfs fix
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Kernel crash/DoS via race in xen_9pfs_front_free during teardown.
Patch when possible
- affected>= c15fe55d14b3b4ded5af2a3260877460a6ffb8ad and < a5d00dff97118a32fcf5fec7a4c3f864c4620c4e
- affected>= c15fe55d14b3b4ded5af2a3260877460a6ffb8ad and < 59e7707492576bdbfa8c1dbe7d90791df31e4773
- affected>= c15fe55d14b3b4ded5af2a3260877460a6ffb8ad and < bf841d43f7a33d75675ba7f4e214ac1c67913065
- affected>= c15fe55d14b3b4ded5af2a3260877460a6ffb8ad and < ce8ded2e61f47747e31eeefb44dc24a2160a7e32
- affectedbe03c4fe72384366fd4077a70966bd3b8fc49013
- affected1ab4de11232e83b875b071aa44d1155634ca8a1e
- affected7cc9dbae8a5f73bd555130384ea256018d28f283
- affected3e0359f151ac151abe3fa71040e450ed69cb824b
- affected8d3fc907d060c4fb33203e616a395a22083b6566
- affected4f0e9244770f5b75a16d8c0929063cd336926764
- affected5f6a8974e9ef317fe63f88bab1f33070195dd147
- affected>= 4.14.308 and < 4.15
- affected>= 4.19.276 and < 4.20
- affected>= 5.4.235 and < 5.5
- affected>= 5.10.173 and < 5.11
- affected>= 5.15.100 and < 5.16
- affected>= 6.1.18 and < 6.2
- affected>= 6.2.5 and < 6.3
- affected6.3
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.