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Vulnerabilities

Vulnerability · CVE-2026-99263

CVE-2026-99263: io_uring/poll: avoid retry wakeup loss when dropping ownership

Published Nov 3, 2026 · catalog updated Nov 3, 2026 · Linux Linux Kernel

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-99263. EPSS is 0.20%. Act only if a listed version of Linux Linux Kernel is installed.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.20%
Remediation
Not established
Affected products
linux kernel · vendor Linux Linux

From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: avoid retry wakeup loss when dropping ownership If a wakeup sets IO_POLL_RETRY_FLAG between the owning task consuming the existing instance of IO_POLL_RETRY_FLAG and the loop check of io_poll_check_events(), then we stall on processing the request until an unrelated wakeup comes along. Using atomic_cmpxchg instead of atomic_sub_return to guarantee both the count v and poll_refs are 0 and no wake-ups are missed. The Linux kernel CVE team has ass

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • linux kernelversion unspecified
  • vendor Linux Linuxversion unspecified

How to fix CVE-2026-99263

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-99263. EPSS is 0.20%. Act only if a listed version of Linux Linux Kernel is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.20%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Nov 3, 2026 · Linux Kernel CVE

    Detected

    From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: avoid retry wakeup loss when dropping ownership If a wakeup sets IO_POLL_RETRY_FLAG between the owning task consuming the existing instance of IO_POLL_RETRY_FLAG and the loop check of io_poll_check_events(), then we stall on processing the request until an unrelated w

  2. Nov 3, 2026 · CVE.org

    Updated

    In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: avoid retry wakeup loss when dropping ownership If a wakeup sets IO_POLL_RETRY_FLAG between the owning task consuming the existing instance of IO_POLL_RETRY_FLAG and the loop check of io_poll_check_events(), then we stall on processing the request until an unrelated wakeup comes along. Using atomic_cmpxchg instead o

Sources

  • CVE.orgVulnerability recordCVE-2026-99263

    In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: avoid retry wakeup loss when dropping ownership If a wakeup sets IO_POLL_RETRY_FLAG between the owning task consuming the existing instance of IO_POLL_RETRY_FLAG and the loop check of io_poll_check

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-99263

    30-day exploitation probability 0.20%

    first.org
  • Linux Kernel CVEVendor advisoryCVE-2026-99263

    CVE-2026-99263 has now been rejected and is no longer a valid CVE.

    git.kernel.org

References

Freshness

Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • Linux Kernel CVENov 7, 2026
  • FIRST EPSSNov 4, 2026
  • CVE.orgNov 4, 2026