Out-of-bounds Read in Catdoc
CVE-2026-111127
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.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- hackmd.io/@haind-pwn/catdoc-xls-mulrk-endcol-and-string-count-oob-read (technical-description)
- github.com/vbwagner/catdoc/blob/38a2807d22ce1a08bc39b94e9072a9f8f52cd86f/src/xl… (technical-description)
- github.com/vbwagner/catdoc (product)
- www.vulncheck.com/advisories/catdoc-through-0.95-out-of-bounds-read-via-xls2csv… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-111127?
- CVE-2026-111127 is a medium-severity vulnerability in Catdoc, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2026-10-15.
- How severe is CVE-2026-111127?
- Medium severity. CVSS v3 base score is 6.1 out of 10.