Medium · CVSS 5.3CVE-2026-107218GHSA-8JJQ-8J9W-M2V6

Excelize: RIGHT() on supplementary-plane text slices with a negative index and panicsCVE-2026-107218

Answer in brief

CVE-2026-107218 records a Medium severity (CVSS 5.3) vulnerability in Excelize: RIGHT() on supplementary-plane text slices with a negative index and panics. The current sources do not mark it as known exploited. The current feed maps qax-os/excelize (generic), github.com/xuri/excelize/v2 (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 7, 2026Updated Oct 7, 2026Source checked Oct 7, 2026First seen by HOL Oct 7, 2026Material review Oct 7, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps qax-os/excelize (generic), github.com/xuri/excelize/v2 (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
qax-os/excelizegeneric	>=2.10.1 <=2.11.0	Not reported
github.com/xuri/excelize/v2go	>=2.10.1,<2.11.1-0.20260908032718-ecd99d761fe0	2.11.1-0.20260908032718-ecd99d761fe0

Recommended response

Check inventory. Check lockfiles and deployed manifests for qax-os/excelize, github.com/xuri/excelize/v2.
Review the reported fix. Update github.com/xuri/excelize/v2 to 2.11.1-0.20260908032718-ecd99d761fe0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 7, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.