A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS()…
Priority HIGH 69CWE-122Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.
Summary
A heap-buffer-overflow and use-after-free vulnerability exists in the xls_getCSS() function of libxls 1.6.3 due to insufficient validation of a file-controlled font index.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00174 6th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
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 |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-79591
- 2026-10-03 Alias added: GHSA-8cvq-g9xh-jmpf
References
Sources
- CVE-2026-79591 · CVE Program
- CVE-2026-79591 · NVD
- FIRST EPSS
- GHSA-8cvq-g9xh-jmpf · GitHub Advisory Database · CC BY 4.0
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