Quick answers
- Is CVE-2026-79592 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-79592 being exploited in the wild.
- How severe is CVE-2026-79592?
- High severity, with a CVSS score of 7.5, published 10 September 2026.
- Which products and versions are affected?
- Libxls 1.6.3.
- Is there a fix for CVE-2026-79592?
- A patch was published on 2026-08-21: Patch merged in PR #165 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-79592 attacked?
- It is attacked over the network or with local access.
- Am I affected by CVE-2026-79592?
- Check whether you run Libxls at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
This is an out-of-bounds read vulnerability (CWE-125) in the xls_dumpSummary() function, which parses OLE SummaryInformation and DocumentSummaryInformation property sets. The vulnerable code performs pointer arithmetic using file-controlled offsets (plist->sectionOffset and secHead->numProperties) without bounds validation, allowing an attacker to craft an XLS file with malicious offset values that cause the parser to read memory outside the allocated summary buffer. Attack vector is network/local (file opening); no authentication is required. The vulnerability enables information disclosure (memory leak) or denial of service (crash). A patch was merged to validate offsets before use.
Affected products
- libxls libxls 1.6.3
Timeline
- 2026-09-10: disclosed
- 2026-08-21: patched: Patch merged in PR #165