Medium severity · published Oct 14, 2026
CVE-2026-110600
xlsxio through 0.2.37 NULL Pointer Dereference via Worksheet Relationship Without Id
5.5
CVSS
0.2%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
XL
xlsxio · brechtsanders
through 0.2.37 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-110600
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-110600
issue-tracking
https://github.com/brechtsanders/xlsxio/issues/151
technical-description
https://github.com/brechtsanders/xlsxio/blob/0.2.37/lib/xlsxio_read.c#L851-L866
third-party-advisory
https://hackmd.io/@haind-pwn/xlsxio-relationship-missing-id-null-deref
third-party-advisory
https://www.vulncheck.com/advisories/xlsxio-through-0.2.37-null-pointer-dereference-via-worksheet-relationship-without-id