CVE-2026-107218 Excelize: RIGHT() on supplementary-plane text slices with a negative index and panics
An attacker can cause a denial of service by triggering a panic in the Excelize library through malformed RIGHT formula arguments on supplementary-plane text.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-107218?
CVE-2026-107218 is a medium-severity denial of service vulnerability in qax-os excelize, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-129
Which versions are affected by CVE-2026-107218?
2 open source packages ship an affected version, including github.com/xuri/excelize/v2. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/xuri/excelize/v2 Go | From 2.10.1 | 2.11.1-0.20260908032718-ecd99d761fe0 |
github.com/xuri/excelize/v2 Go | From 2.10.1 | 2.11.1-0.20260908032718-ecd99d761fe0 |
Products include Excelize Excelize.
How do I fix CVE-2026-107218?
Upgrade github.com/xuri/excelize/v2 to 2.11.1-0.20260908032718-ecd99d761fe0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-107218 being exploited?
There is no known exploitation of CVE-2026-107218 in the wild and no public exploit code.
Other vulnerabilities in qax-os excelize
- CVE-2026-107211 Excelize: Unchecked pivot-cache field index in extractPivotTableFields causes unrecoverable panic
- CVE-2026-107213 Excelize: Nil-pointer dereference in GetSlicers when a worksheet has extLst present but no drawing element
- CVE-2026-59161 Excelize: Streaming GetRows row-bound bypass causes attacker-controlled allocation
- CVE-2026-107212 Excelize: Unbounded row number in Rows.Columns makes GetRows and the Rows iterator loop for days
- CVE-2026-107214 Excelize Decrypt: unrecoverable panics on malformed OLE/CFB encrypted workbooks
Sources
Also known as GHSA-8jjq-8j9w-m2v6.