NULL pointer dereference in Brechtsanders Xlsxio
CVE-2026-110600
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/brechtsanders/xlsxio/issues/151 (issue-tracking)
- github.com/brechtsanders/xlsxio/blob/0.2.37/lib/xlsxio_read.c (technical-description)
- hackmd.io/@haind-pwn/xlsxio-relationship-missing-id-null-deref (third-party-advisory)
- www.vulncheck.com/advisories/xlsxio-through-0.2.37-null-pointer-dereference-via… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-110600?
- CVE-2026-110600 is a medium-severity vulnerability in Brechtsanders Xlsxio, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-10-14.
- How severe is CVE-2026-110600?
- Medium severity. CVSS v3 base score is 5.5 out of 10.