VulnerabilityPublished 3 Nov 2026

CVE-2026-99264: Linux kernel · io_uring/net: don't retry recv on uncommitted buffers

Source GCVE Database

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Authoritative record:CVE-2026-99264· High

Not known to be exploited · fixed in fc8506eea4498ecba26ef8bf6dbbd74af3dc891d : patch Linux kernel soon.

Data as of 3 Nov 2026, 13:15 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in fc8506eea4498ecba26ef8bf6dbbd74af3dc891d, 97b8dc36ba3cb176b74a7929140aeaeb40d5cdc0, 21cb1770a56a51266ab96d4ed2a3b6979db59694 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-q4wp-8vpq-9rg3

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=6.12.44 <6.12.115 >=6.6.103 <6.7 >=6.15.11 <6.16 >=6.16.2 <6.17	Fixed in fc8506eea4498ecba26ef8bf6dbbd74af3dc891d 97b8dc36ba3cb176b74a7929140aeaeb40d5cdc0 21cb1770a56a51266ab96d4ed2a3b6979db59694 6.17 6.16 6.12.115 6.7
LinuxLinux	Affected =6.17	Fixed in–

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel via commit 41b70df5b38b. Users should apply the updated kernel version containing this patch to resolve the issue. Since this is a kernel-level fix, updating to the patched kernel release is the recommended remediation. No alternative mitigations or workarounds are indicated.

Description

CVE-2026-99264 is a vulnerability in the Linux kernel's io_uring/net subsystem related to how receive operations retry on uncommitted buffers. The issue involves improper handling of partial buffer commits during retries, which can cause data corruption by allowing multiple requests to write to the same memory buffers concurrently. The fix changes the behavior to complete the request with the data received so far instead of retrying, and MSG_WAITALL is no longer honored for incremental or multi-buffer bundles.

Impact

The vulnerability can cause data corruption due to concurrent writes to the same memory buffers by multiple receive requests. Applications relying on io_uring for network receive operations may receive inconsistent or corrupted data, potentially impacting data integrity. There is no indication of remote code execution or privilege escalation. No known exploits in the wild have been reported.

Summary

This vulnerability in the Linux kernel io_uring/net subsystem arises from the retry logic on receive operations using buffer rings or bundles. Previously, partial buffers were not fully committed when a receive was retried, causing subsequent requests to reuse memory still being written to by the retried request. This led to data being overwritten and inconsistencies between what the kernel reported as consumed and what was actually written. The patch commits partial buffers on retry and changes the behavior to complete the request with the bytes received so far, disabling MSG_WAITALL semantics for incremental or multi-buffer receives to prevent this issue.

References

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