CVE-2026-110600: NULL Pointer Dereference in brechtsanders xlsxio
Description
xlsxio through 0.2.37 contains a NULL pointer dereference vulnerability in main_sheet_get_sheetfile_expat_callback_element_start() in lib/xlsxio_read.c that allows attackers to crash applications via crafted files. Attackers can supply a .xlsx file whose workbook.xml.rels contains a worksheet Relationship lacking an Id attribute, crashing the process when xlsxioread_sheet_open() is called.
CVSS v4.0
Score 6.8medium
Affected software
brechtsanders
xlsxio
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
xlsxio versions up to and including 0.2.37 contain a NULL pointer dereference vulnerability in the main_sheet_get_sheetfile_expat_callback_element_start() function located in lib/xlsxio_read.c. The issue arises when processing a specially crafted .xlsx file whose workbook.xml.rels file includes a worksheet Relationship element lacking the required Id attribute. This causes the application to dereference a NULL pointer, resulting in a crash during the call to xlsxioread_sheet_open().
Potential Impact
An attacker can cause a denial of service by crashing applications that use vulnerable versions of xlsxio when they open a maliciously crafted .xlsx file. There is no indication of code execution or data disclosure from the provided information.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid processing untrusted .xlsx files or implement input validation to detect missing Id attributes in worksheet Relationships.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-14T13:07:20.207Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6acf92e92cdf04f6568a2e1a
Added to database: 10/14/2026, 14:34:17 UTC
Last enriched: 10/14/2026, 15:18:44 UTC
Last updated: 10/14/2026, 21:19:00 UTC
Views: 9
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