CVE-2026-111127

Description

catdoc through 0.95 contains an out-of-bounds read vulnerability in copy_unicode_string() in src/xlsparse.c that allows attackers to read past buffers via an unchecked string character count. Attackers can supply a crafted .xls file declaring 0xFFFF two-byte characters in LABEL, STRING, or SST records to disclose adjacent memory through xls2csv output or crash the process.

References

• https://github.com/vbwagner/catdoc
• https://github.com/vbwagner/catdoc/blob/38a2807d22ce1a08bc39b94e9072a9f8f52cd86f/src/xlsparse.c#L421-L520
• https://hackmd.io/@haind-pwn/catdoc-xls-mulrk-endcol-and-string-count-oob-read
• https://www.vulncheck.com/advisories/catdoc-through-0.95-out-of-bounds-read-via-xls2csv-copy-unicode-string