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TI-2026-21391 Aliases CVE-2026-26824GHSA-hwmf-9wj8-35pw

libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the…

Priority HIGH 68CWE-457Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · None · Low
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.

Summary

libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser. Memory allocated for the Master Sector Allocation Table (MSAT) in read_MSAT() is not fully initialized before being consumed by ole2_validate_sector_chain(), which may result in application crashes or potential information disclosure when processing a crafted XLS file

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0027 19th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:libxls_project:libxls:*:*:*:*:*:*:*:*up to 1.6.3Vulnerablelibxls
  • cpe:2.3:a:libxls_project:libxls:*:*:*:*:*:*:*:* Versions up to 1.6.3 Vulnerable ·libxls

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-26824
  2. 2026-10-03 Alias added: GHSA-hwmf-9wj8-35pw

References

Exploit 1

Other 2

  • TI-2023-20133 Buffer Overflow vulnerability in libxlsv.1.6.2 allows a remote attacker to execute… CVSS 3.1MEDIUM 6.5
  • TI-2023-20132 Buffer Overflow vulnerability in libxlsv.1.6.2 allows a remote attacker to execute… CVSS 3.1MEDIUM 6.5
  • TI-2023-20131 Buffer Overflow vulnerability in libxlsv.1.6.2 allows a remote attacker to execute… CVSS 3.1MEDIUM 6.5
  • TI-2023-20130 Buffer Overflow vulnerability in libxlsv.1.6.2 allows a remote attacker to execute… CVSS 3.1MEDIUM 6.5
  • TI-2023-20128 Buffer Overflow vulnerability in libxlsv.1.6.2 allows a remote attacker to execute… CVSS 3.1MEDIUM 6.5
  • TI-2017-08902 Integer overflow in libxls CVSS 3.0HIGH 8.8
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences