CVE-2026-107223VulnerabilityPublished 7 Oct 2026Updated 10 Nov 2026

github.com/xuri/excelize/v2 · Excelize: Unbounded <col max> attribute is loaded with no MaxColumns check and expanded per-column by flatCols(), so

Affects github.com/xuri/excelize/v2Source GCVE Database

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Authoritative record:CVE-2026-107223· High 7.1

Not known to be exploited · CVSS 7.1 High : upgrade to 2.11.1 soon.

Data as of 10 Nov 2026, 20:05 UTC

CVSS 4.0 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 2.11.1

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: Passive
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: High
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 7 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade github.com/xuri/excelize/v2 to 2.11.1.

Affected software

Product	Affected	Fixed in
Gogithub.com/xuri/excelize/v2	Affected >=2.1.0 <2.11.1	Fixed in 2.11.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### Summary The `max` attribute of a `<col>` element in `xl/worksheets/sheetN.xml` is read verbatim on open with no check against `MaxColumns`, and `flatCols()` then walks `Min..Max` doing a `deepcopy.Copy` and `append` per iteration. Executed: `max="300000"`, only about 18x past the real 16384 limit, cost 46.2 s of CPU and 122 MB on a single `SetColWidth` call, and the growth is linear in `max` up to 2^31-1. Confirmed at `ae2113b` (HEAD at the time of audit). ### Details `col.go:547`, `flatCols()`, with the two loops at `:549` and `:564`: ```go for i := col.Min; i <= col.Max; i++ { ... for i := column.Min; i <= column.Max; i++ { ... fc = append(fc, deepcopy.Copy(...)) } ``` `column.Min` and `column.Max` are plain int attributes on `xmlWorksheet.go:279-280`, bound straight from the file. `MaxColumns` is 16384 (`templates.go:176`) and nothing in the parse path compares against it. The contrast that makes this an oversight rather than a design decision is inside the callers themselves. `SetColWidth` validates its own column argument through `parseColRange`, which clamps to `MaxColumns`. But `flatCols` iterates `ws.Cols.Col`, the file-loaded slice, so the caller's validated argument never constrains the loop. The crafted column expands no matter which column the caller touches. The row axis has the guard this axis is missing: GHSA-h69g-9hx6-f3v4 capped `checkSheet`'s row allocation at `TotalRows`, and GHSA-q5j5-6p94-4gwc capped streaming `Rows.Next`. There is no column-axis equivalent. Public entry points that flatten the existing columns: `SetColWidth` (`col.go:498` into `:534`), `SetColStyle` (`col.go:431` into `:477`), `SetColVisible` (`col.go:282` into `:313`), `SetColOutlineLevel` (`col.go:376` into `:407`). ### PoC Executed in-package: crafted a real xlsx, rezipped with an injected `<cols>` block before `<sheetData>`, opened it with `OpenReader`, then called `SetColWidth`. ```xml <cols><col min="1" max="2147483647" width="9"/></cols> ``` ```go f.SetColWidth("Sheet1", "A", "A", 12) ``` Measured: - `max="300000"`: 46.2 s CPU, 122 MB allocated, `ws.Cols.Col` grew to 300000 entries, from one call. - `max="5000000"`: did not complete in 110 s, killed by the test timeout. Growth is linear in `max`. At `max=2147483647` that is roughly two billion `xlsxCol` allocations, which is hundreds of gigabytes and in practice a permanent hang ending in OOM. ### Impact Any service that opens an untrusted spreadsheet and calls a column mutator. The input is a few dozen bytes of XML inside an otherwise ordinary workbook, no authentication is involved beyond whatever gates the upload, and the process is either wedged for minutes or killed by the OOM reaper. Availability only; no read or write primitive here. ### Suggested fix Validate `col.Min` and `col.Max` against `MinColumns`/`MaxColumns` when parsing the `<col>` element, or at the top of `flatCols`, returning `ErrColumnNumber` for out-of-range values. That mirrors what `checkRowNum` already does on the row axis. ### Why this is not GHSA-h69g-9hx6-f3v4 or GHSA-q5j5-6p94-4gwc Both of those are row-axis allocation bounds, and both fixes cap at `TotalRows`. Neither touched `<col>` parsing or `flatCols`. This is the same weakness class on the column axis, and it is arguably worse than the two that were fixed, because those had a cap that was bypassed while this one has no cap at all.

CWE-789Memory Allocation with Excessive Size Value (opens in a new tab)
Variant weakness
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
Implementation · Architecture and Design
Perform adequate input validation against any value that influences the amount of memory that is allocated. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.
Operation
Run your program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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WeaknessesCWE-789

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