CVE-2026-99042: Linux kernel · io_uring/net: populate CONNECT filter fields for 24-byte sockaddr_in6
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 8.4 High : upgrade to aa5d5f8e502318e783545ba5d04bb40130b83e20 or 596a955d2d01b7e29d9fed60ebcf7c4ba518b8e5 soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in aa5d5f8e502318e783545ba5d04bb40130b83e20, 596a955d2d01b7e29d9fed60ebcf7c4ba518b8e5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade Linux kernel to aa5d5f8e502318e783545ba5d04bb40130b83e20 or 596a955d2d01b7e29d9fed60ebcf7c4ba518b8e5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix for this vulnerability is available and has been applied in Linux kernel versions after 7.2, as indicated by the fixed commits. Users should upgrade to a fixed kernel version containing the patches identified by commits aa5d5f8e502318e783545ba5d04bb40130b83e20 and 596a955d2d01b7e29d9fed60ebcf7c4ba518b8e5. No additional mitigation is required if running a patched kernel.
Description
CVE-2026-99042 is a vulnerability in the Linux kernel's io_uring networking code where a mismatch in address length checks allows bypassing of IPv6 connect filters. Specifically, the filter fields for connect.port and connect.v6_addr are not populated correctly for 24-byte sockaddr_in6 structures, causing filters that deny certain IPv6 ports or addresses to be bypassed. This issue has been fixed by adjusting the threshold to use SIN6_LEN_RFC2133 (24 bytes) as the correct length check.