CVE-2026-3463: xlnt-community xlnt Compound Document binary.hpp append heap-based overflow

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-03 · updated 2026-06-17
Weakness: CWE-119

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.

Affected products

xlnt-community xlnt: through 1.6.1

References

https://github.com/oneafter/0128/blob/main/xl2/repro
https://github.com/xlnt-community/xlnt/
https://github.com/xlnt-community/xlnt/issues/138
https://github.com/xlnt-community/xlnt/issues/138#issuecomment-3868381672
https://github.com/xlnt-community/xlnt/pull/147
https://vuldb.com/?ctiid.348530
https://vuldb.com/?id.348530
https://vuldb.com/?submit.764643

Get alerted when CVE-2026-3463 or the next vulnerability affects your stack