What’s Vulnerable › Vulnerabilities

CVE-2026-111127: catdoc through 0.95 Out-of-Bounds Read via xls2csv copy_unicode_string

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-15 · updated 2026-10-16
• Weakness: CWE-125

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.

Affected products

• catdoc: through 0.95

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

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