CVE-2026-53306HighMicrosoft CVSS 7.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Microsoft advisory for CVE-2026-53306 — azl3 kernel 6.6.139.1-1 on Azure Linux 3.0

Published
June 30, 2026
Last Modified
—

🔗 CVE IDs covered (1)

📋 Microsoft's advisory

EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53306. This page also shows what EchelonGraph holds for CVE-2026-53306, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.

🎯 Affected products1

  • azl3 kernel 6.6.139.1-1 on Azure Linux 3.0

🧭 EchelonGraph on CVE-2026-53306

EchelonGraph score
5.5 MEDIUM
CISA KEV
Not listed
Fix status
A fix is available — apply it.

Description from the CVE record (CVE.org), as published by its numbering authority

In the Linux kernel, the following vulnerability has been resolved: tty: hvc_iucv: fix off-by-one in number of supported devices MAX_HVC_IUCV_LINES == HVC_ALLOC_TTY_ADAPTERS == 8. This is the number of entries in: static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; Sometimes hvc_iucv_table[] is limited by: (a) if (num > hvc_iucv_devices) // for error detection or (b) for (i = 0; i < hvc_iucv_devices; i++) // in 2 places (so these 2 don't agree; second one appears to be correct to me.) hvc_iucv_devices can be 0..8. This is a counter. (c) if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) If hvc_iucv_devices == 8, (a) allows the code to access hvc_iucv_table[8]. Oops.

Published by kernel.org, the CVE Numbering Authority that assigned CVE-2026-53306, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).

🔗 References (1)