CVE-2026-3463 xlnt-community xlnt Compound Document binary.hpp append heap-based overflow
A heap-based buffer overflow in the xlnt library's Compound Document parser allows local attackers to execute arbitrary code or cause denial of service.
- 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-2026-3463?
CVE-2026-3463 is a medium-severity memory corruption vulnerability in xlnt-community xlnt, published on 3 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A weakness has been identified in xlnt-community xlnt up to 1.6.1. Impacted is the function xlnt::detail::binary_writer::append of the file source/detail/binary.hpp of the component Compound Document Parser. This manipulation causes heap-based buffer overflow. The attack can only be executed locally. The exploit has been made available to the public and could be used for attacks. Patch name: 147. It is suggested to install a patch to address this issue.
Which versions are affected by CVE-2026-3463?
It affects 1 product.
Products include Xlnt-Community Xlnt.
How do I fix CVE-2026-3463?
No fix has been published for CVE-2026-3463 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-2026-3463 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3463 exists.
Other vulnerabilities in xlnt-community xlnt
- CVE-2026-3663 xlnt-community xlnt XLSX File compound_document.cpp xsgetn out-of-bounds
- 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-2026-2703 xlnt-community xlnt Encrypted XLSX File base64.cpp decode_base64 off-by-one
Sources
Also known as GHSA-hhjx-x77r-qp36.