Buffer overflow in Xlnt-Community Xlnt
CVE-2026-3663
A vulnerability was found in xlnt-community xlnt up to 1.6.1. This issue affects the function xlnt::detail::compound_document_istreambuf::xsgetn of the file source/detail/cryptography/compound_document.cpp of the component XLSX File Parser. Performing a manipulation results in out-of-bounds read. The attack is only possible with local access. The exploit has been made public and could be used. The patch is named 147. It is recommended to apply a patch to fix this issue.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.002 (8.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 8.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Xlnt-Community Xlnt — versions 1.6.0, 1.6.1
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/ (VDB Entry, Third Party Advisory, third-party-advisory)
- github.com/xlnt-community/xlnt/issues/139 (issue-tracking, Exploit, Issue Tracking, Vendor Advisory)
- github.com/oneafter/0128/blob/main/xl3/repro (Exploit, exploit)
- github.com/xlnt-community/xlnt/pull/147 (issue-tracking, patch, Issue Tracking)
- github.com/xlnt-community/xlnt/ (Product, product)
Frequently asked questions
- What is CVE-2026-3663?
- CVE-2026-3663 is a low-severity vulnerability in Xlnt-Community Xlnt, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 3.3/10. Published 2026-03-07.
- How severe is CVE-2026-3663?
- Low severity. CVSS v3 base score is 3.3 out of 10.