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.

CVSS 4.0

6.8CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

5.5CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 14% of CVEs (scores of 2026-10-25)

CWE

CWE-476

Published

2026-10-14

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

References

• https://github.com/brechtsanders/xlsxio/blob/0.2.37/lib/xlsxio_read.c#L851-L866
• https://github.com/brechtsanders/xlsxio/issues/151
• https://hackmd.io/@haind-pwn/xlsxio-relationship-missing-id-null-deref
• https://www.vulncheck.com/advisories/xlsxio-through-0.2.37-null-pointer-dereference-via-worksheet-relationship-without-id
• https://github.com/brechtsanders/xlsxio/issues/151

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