Skip to content
major vulnerability· requires attention

Linux kernel vulnerability affects widespread OS deployments and can lead to kernel compromise; likely to impact many organizations and warrant broad attention.

Systems

CVE-2026-90151

9.8
Critical
EPSS n/aPatch availableSep 19, 2026

Linux kernel NFSv4 use-after-free in callback handling causing kernel memory corruption.

common questions

Is CVE-2026-90151 being exploited?

Not confirmed. CVE-2026-90151 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.

How severe is CVE-2026-90151?

CVE-2026-90151 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-2026-90151?

Yes. A fix has been recorded for CVE-2026-90151. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2026-90151 affect?

CVE-2026-90151 affects Linux kernel (NFSv4 client subsystem), Linux distributions with affected kernels, Clients mounting untrusted NFSv4 servers. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-90151?

Apply vendor kernel updates immediately; avoid mounting untrusted NFSv4 servers.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
Linux kernel (NFSv4 client subsystem)Linux distributions with affected kernelsClients mounting untrusted NFSv4 servers
impact

Use-after-free in NFSv4 callback can lead to kernel memory corruption, enabling privilege escalation or kernel crash; can be triggered by malicious NFS server or local actions.

action required

Immediate action required

affected versions
Linux Linux
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < 68c721391b761dbe38d5b0094d2bb6e8489ad92b
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < 9bfdd0f591307b5198826a0e7a5b2f35f87acd2d
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < 7c4812eb96bdcafb31a65b12f2aa96659429d1d4
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < fc95ca82d5ae598c428ab5a00ae69f8526d59371
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < 80b1c3d5a881f7d9081aa9f46da9742878a0f893
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < 3f2387e8bfbc4efda5d77c3a11a028d0a119c48f
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < 5891c03e150920618db0e9c4ea2d772abacdcfd1
  • affected>= f4eecd5da3422e82e88e36c33cbd2595eebcacb1 and < d05c2007b3d84ccba11dc6e9cb3202768cc72f14
  • affected2.6.38
vendor says fixed in< 2.6.38, >= 5.10.270 and <= 5.10.*, >= 5.15.221 and <= 5.15.*, >= 6.1.188 and <= 6.1.*, >= 6.6.157 and <= 6.6.*, >= 6.12.110 and <= 6.12.*, >= 6.18.52 and <= 6.18.*, >= 7.2.6 and <= 7.2.*, >= 7.3-rc1 and <= *

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.

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
get alerted

Track only the vulnerabilities that affect your infrastructure.

start for free