NULL pointer dereference in xlsxio lets crafted files crash apps
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-476.
Summary
xlsxio through 0.2.37 contains a NULL pointer dereference in main_sheet_get_sheetfile_expat_callback_element_start() in lib/xlsxio_read.c (CWE-476). A worksheet Relationship in workbook.xml.rels that lacks an Id attribute crashes the process when xlsxioread_sheet_open() is called. An attacker can supply such a crafted .xlsx file to crash applications that use the library.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| brechtsanders | xlsxio | up to 0.2.37 | — | No fix listed | CNA |
- xlsxio Vendorbrechtsanders Affected up to 0.2.37 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for xlsxio.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Timeline
- 2026-10-14 Threatist record created from CVE-2026-110600
- 2026-10-14 Alias added: GHSA-6j5v-fg26-wg57
- 2026-10-15 CISA SSVC decision points changed
References
Sources
- CVE-2026-110600 · CVE Program
- CVE-2026-110600 · NVD
- FIRST EPSS
- GHSA-6j5v-fg26-wg57 · GitHub Advisory Database · CC BY 4.0
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