# 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. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 7 Oct 2026 - **Updated:** 10 Oct 2026 - **Also known as:** GHSA-x2q3-8cjh-766f, GO-2026-6689 ## 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 (Memory Allocation with Excessive Size Value) ## 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 | Ecosystem | 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: Excelize Excelize. ## How do I fix CVE-2026-107215? Upgrade github.com/xuri/excelize/v2 to 2.11.1-0.20260912113515-5f636f9dcde5 or later. ## 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](https://insights.sbomify.com/CVE-2026-107211/): Excelize: Unchecked pivot-cache field index in extractPivotTableFields causes unrecoverable panic (high 8.7) - [CVE-2026-107213](https://insights.sbomify.com/CVE-2026-107213/): Excelize: Nil-pointer dereference in GetSlicers when a worksheet has extLst present but no drawing element (high 8.7) - [CVE-2026-59161](https://insights.sbomify.com/CVE-2026-59161/): Excelize: Streaming GetRows row-bound bypass causes attacker-controlled allocation (high 8.7) - [CVE-2026-107212](https://insights.sbomify.com/CVE-2026-107212/): Excelize: Unbounded row number in Rows.Columns makes GetRows and the Rows iterator loop for days (high 7.5) - [CVE-2026-107214](https://insights.sbomify.com/CVE-2026-107214/): Excelize Decrypt: unrecoverable panics on malformed OLE/CFB encrypted workbooks (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-107215 and fix it if it is affected. What it is: 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. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-107215 exists. Affected packages and fixed versions: - github.com/xuri/excelize/v2 (Go): affected all versions; fixed in 2.11.1-0.20260912113515-5f636f9dcde5 - github.com/xuri/excelize/v2 (Go): affected from 2.3.1; fixed in 2.11.1-0.20260912113515-5f636f9dcde5 - github.com/xuri/excelize/v2 (Go): affected from 2.3.1; fixed in 2.11.1-0.20260912113515-5f636f9dcde5 - github.com/360EntSecGroup-Skylar/excelize/v2 (Go): affected from 2.3.1; no fix listed Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-107215/ (Markdown: https://insights.sbomify.com/CVE-2026-107215/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107215 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107215 - OSV: https://osv.dev/vulnerability/CVE-2026-107215 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-107215/ Summaries are generated and may contain mistakes; the official description above is the record.