Microsoft security update for CVE-2026-34990
🔗 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-2026-34990. This page also shows what EchelonGraph holds for CVE-2026-34990, 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 products3
- azl3 cups 2.4.16-1 on Azure Linux 3.0
- cbl2 cups 2.3.3op2-11 on CBL Mariner 2.0
- cbl2 cups 2.3.3op2-11 on CBL-Mariner 2.0
✅ Updates Microsoft lists: 2 updates
2 rows: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.
| KB article | Update | Fixed build |
|---|---|---|
| — | Security Update | 2.4.17-1 |
| — | Security Update | — |
🧭 EchelonGraph on CVE-2026-34990
- EchelonGraph score
- 7.8 HIGH
- 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
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, a local unprivileged user can coerce cupsd into authenticating to an attacker-controlled localhost IPP service with a reusable Authorization: Local ... token. That token is enough to drive /admin/ requests on localhost, and the attacker can combine CUPS-Create-Local-Printer with printer-is-shared=true to persist a file:///... queue even though the normal FileDevice policy rejects such URIs. Printing to that queue gives an arbitrary root file overwrite; the PoC below uses that primitive to drop a sudoers fragment and demonstrate root command execution. At time of publication, there are no publicly available patches.
Published by GitHub, Inc., the CVE Numbering Authority that assigned CVE-2026-34990, 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).