CVE-2026-3663 xlnt-community xlnt XLSX File compound_document.cpp xsgetn out-of-bounds
A local attacker can trigger an out-of-bounds read in the xlnt library via a crafted XLSX file, potentially causing crashes or data exposure.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-3663?
CVE-2026-3663 is a medium-severity memory corruption vulnerability in xlnt-community xlnt, published on 7 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-3663?
It affects 1 product.
Products include Xlnt-Community Xlnt.
How do I fix CVE-2026-3663?
No fix has been published for CVE-2026-3663 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-3663 being exploited?
There is no known exploitation of CVE-2026-3663 in the wild and no public exploit code.
Other vulnerabilities in xlnt-community xlnt
- CVE-2026-3664 xlnt-community xlnt Encrypted XLSX File compound_document.cpp read_directory out-of-bounds
- CVE-2026-3665 xlnt-community xlnt XLSX File xlsx_consumer.cpp read_office_document null pointer dereference
- CVE-2026-3463 xlnt-community xlnt Compound Document binary.hpp append heap-based overflow
- CVE-2026-2703 xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-one
Sources
Also known as GHSA-6v7x-r5hj-8xc6.