CVE-2026-107215 Excelize: extractPart allocates attacker-controlled, unbounded and negative-sized buffers from CFB directory entries: remote panic / OOM DoS
Attackers can cause application crashes or memory exhaustion by providing crafted Excel files with invalid CFB directory entries.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-107215?
CVE-2026-107215 is a high-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 2.3.1 to 2.11.0, extractPart allocates a byte slice directly from an attacker-controlled CFB directory-entry size before validating the sector chain or size domain. extractPart trusts the CFB directory entry streamSize for EncryptionInfo and EncryptedPackage allocations before validating the stream. When a crafted OLE compound file declares a negative or extremely large EncryptionInfo or EncryptedPackage stream size, the declared size reaches make with a negative length or forces a multi-gigabyte allocation, allowing an attacker to panic or exhaust process memory. No fixed version is available as of this review.
Weakness: CWE-789
Which versions are affected by CVE-2026-107215?
4 open source packages ship an affected version, including github.com/xuri/excelize/v2 and github.com/360EntSecGroup-Skylar/excelize/v2. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/xuri/excelize/v2 Go | All versions | 2.11.1-0.20260912113515-5f636f9dcde5 |
github.com/xuri/excelize/v2 Go | From 2.3.1 | 2.11.1-0.20260912113515-5f636f9dcde5 |
github.com/xuri/excelize/v2 Go | From 2.3.1 | 2.11.1-0.20260912113515-5f636f9dcde5 |
github.com/360EntSecGroup-Skylar/excelize/v2 Go | From 2.3.1 | None |
Products include Excelize Excelize.
How do I fix CVE-2026-107215?
Upgrade github.com/xuri/excelize/v2 to 2.11.1-0.20260912113515-5f636f9dcde5 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-2026-107215 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-107215 exists.
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-x2q3-8cjh-766f, GO-2026-6689.