Microsoft security update for CVE-2026-115819 — 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-2026-115819. This page also shows what EchelonGraph holds for CVE-2026-115819, 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-2026-115819
- EchelonGraph score
- 4.8 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 the wide scanf family of functions (swscanf, fwscanf, wscanf, vswscanf, vfwscanf and vwscanf) with a %s or %[ conversion without the 'l' length modifier in the GNU C Library version 2.2 to version 2.44 writes an extra null byte one past the end of the destination array when the converted multibyte string and its terminating null byte exactly fill that array. These conversions store each wide input character into the caller's char array as a multibyte sequence. The conversion ends with the sequence that returns to the initial shift state, which also stores the terminating null byte, and the functions then append a second null byte. A destination sized for the converted string and one terminator, as the C standard requires the caller to provide, is therefore written one byte past its end. The out-of-bounds byte is always a null byte, which may corrupt adjacent data or crash the process. An attacker who supplies the input can trigger the overflow with a string whose converted length exactly fills the destination. The narrow scanf functions, the %ls and %l[ conversions into a wchar_t array, and the 'a' and 'm' allocation modifiers are not affected, and storing a wide scanf conversion into a narrow char array is uncommon. This issue affects all architectures and ABIs supported by the GNU C Library.
Published by GNU C Library, the CVE Numbering Authority that assigned CVE-2026-115819, 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).