CVE-2026-110600

MEDIUM 5.5

xlsxio through 0.2.37 NULL Pointer Dereference via Worksheet Relationship Without Id

CVSS Score

5.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-476
Vendor	brechtsanders
Product	xlsxio
Published	Oct 14, 2026

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CVSS v3 Breakdown

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

brechtsanders / xlsxio

0 ≤ 0.2.37

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

pedrobtz HaiND from the Post and Telecommunication Institute of Technology