What is CVE-2026-107218?

CVE-2026-107218 is a medium-severity vulnerability in Qax-Os Excelize, classified under Improper Validation of Array Index. CVSS score: 5.3/10. Published 2026-10-07.

How severe is CVE-2026-107218?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Qax-Os Excelize

CVE-2026-107218

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.10.1 to 2.11.0, RIGHT validates the requested length with UTF-16 code-unit counts but slices a rune array using Unicode code-point counts. RIGHT reaches leftRight through CalcCellValue, where countUTF16String validates one unit but utf8.RuneCountInString supplies the slice index in another. When RIGHT evaluates supplementary-plane text with a requested character count between the rune count and UTF-16 code-unit count, the inconsistent units produce a negative rune-slice index, allowing an attacker to panic during formula evaluation. No fixed version is available as of this review.

Published 2026-10-07 · last modified 2026-10-07.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

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

Qax-Os Excelize — versions >= 2.10.1, <= 2.11.0

Weakness classification (CWE)

CWE-129 — Improper Validation of Array Index

References

Frequently asked questions

What is CVE-2026-107218?: CVE-2026-107218 is a medium-severity vulnerability in Qax-Os Excelize, classified under Improper Validation of Array Index. CVSS score: 5.3/10. Published 2026-10-07.
How severe is CVE-2026-107218?: Medium severity. CVSS v3 base score is 5.3 out of 10.