Microsoft security update for CVE-2026-19542 — azl3 glibc 2.38-21 on Azure Linux 3.0
🔗 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-2026-19542. This page also shows what EchelonGraph holds for CVE-2026-19542, 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 glibc 2.38-21 on Azure Linux 3.0
✅ Updates Microsoft lists: 1 update
1 row: 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 | — |
🧭 EchelonGraph on CVE-2026-19542
- EchelonGraph score
- 5.6 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
Calling tdelete on a sufficiently deep tree in the GNU C Library version 2.1 to 2.44 may write one pointer past the end of an alloca-allocated array on the stack, which may crash the application. The tdelete implementation keeps an explicit stack of parent nodes for rebalancing, which is grown as needed while descending the tree. Two rebalancing branches push an additional entry without checking the capacity, and write past the array when the stack is exactly full. Triggering this requires a node at a depth of exactly 40 (or 40 plus a multiple of 20), which implies a tree with at least a million nodes, so an attacker must drive a large number of insertions and deletions through an application that uses tsearch and tdelete. The written value is a pointer into a tree node and is not directly attacker controlled. No affected application in common distributions has been identified.
Published by GNU C Library, the CVE Numbering Authority that assigned CVE-2026-19542, 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).