Vulnerability-Lookup

GHSA-WP2G-VPJJ-G53R

Vulnerability from github – Published: 2026-10-08 16:31 – Updated: 2026-10-08 16:31

Summary

Excelize ANCHORARRAY: mutually-referencing array formulas recurse unboundedly via re-entrant CalcCellValue, causing a fatal stack overflow

Details

Summary

ANCHORARRAY (calc.go:15137 on current master) evaluates each cell of the referenced spill range by calling the exported CalcCellValue, which unconditionally constructs a fresh calcContext — fresh entry marker, fresh iterations map, full MaxCalcIterations budget (calc.go:896-900). The circular-reference control only exists within one context: the entry-exclusion marker and per-ref iteration budget are fields of that single context, and completion-based caching (formulaArgCache/calcRawCache) only ever stores results of evaluations that finish.

During a pure cycle no nested evaluation ever finishes, so nothing is ever cached to break the recursion, and each hop re-arms the entire budget. Two ordinary, Excel-legal constructs in an attacker-supplied workbook are enough:

A1 (dynamic array formula, ref A1:A1): _xlfn.ANCHORARRAY($B$1)
B1 (dynamic array formula, ref B1:B1): _xlfn.ANCHORARRAY($A$1)

→ CalcCellValue → calcCellValue → evalInfixExp → parseReference → cellResolver → … → ANCHORARRAY → CalcCellValue → … forever, ending in a fatal, unrecoverable Go runtime error: runtime: goroutine stack exceeds …-byte limit / fatal error: stack overflow. Go stack overflows cannot be recovered — the whole process aborts.

Details

The terminating edge the iterations gate is supposed to provide does not exist across contexts: there is no in-flight tracking shared between nested CalcCellValue calls.
Both formulas are ordinary Excel-legal constructs; no exotic XML is required.
Excelize's own APIs reach formula evaluation on untrusted cells implicitly (e.g. pivotTable.go:538, picture.go:985/1141, col.go:892), so a service that merely adds a pivot table or a picture over such a workbook dies.
No option value prevents it: MaxCalcIterations is irrelevant because every hop gets a fresh budget.
Measured: a 64 MB stack budget is exhausted in ~0.09 s; the ~1 GB default in ~1–2 s.

PoC

A standalone program (public API only) was provided to the maintainer by email (4-anchorarray-recursion): NewFile + SetCellFormula with FormulaOpts{Type: array, Ref: A1:A1 / B1:B1}, then CalcCellValue("Sheet1","A1"). On master ecd99d761fe0 (2026-09-08) the process aborts with fatal error: stack overflow; with the proposed patch the cycle terminates normally (CYCLE_TERMINATED) and existing calc tests pass.

Impact

An attacker ships a workbook containing the two formulas; any service that evaluates a formula over those cells — directly via CalcCellValue, or implicitly via AddPivotTable / AddPicture / auto-fit — aborts. Remote, unauthenticated, process-fatal, no configuration prevents it.

Proposed fix

Evaluate spill-range cells through the current calculation context — fn.f.cellResolver(fn.ctx, …) instead of the exported CalcCellValue — so the entry check and iterations gate of the running calculation apply. cellResolver returns the typed value directly (dropping a string round-trip); an ArgEmpty → "" shim preserves the existing ToNumber behavior for empty spill cells, and a fresh-context fallback covers the legacy nil-ctx test paths. A complete patch has been provided to the maintainer.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/xuri/excelize/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.8.1"
            },
            {
              "fixed": "2.11.1-0.20260911060113-ea12859e43c6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-107216"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-08T16:31:21Z",
    "nvd_published_at": "2026-10-07T18:17:19Z",
    "severity": "HIGH"
  },
  "details": "### Summary\n\n`ANCHORARRAY` (calc.go:15137 on current master) evaluates each cell of the referenced spill range by calling the **exported** `CalcCellValue`, which unconditionally constructs a fresh `calcContext` \u2014 fresh entry marker, fresh iterations map, full `MaxCalcIterations` budget (calc.go:896-900). The circular-reference control only exists **within one context**: the entry-exclusion marker and per-ref iteration budget are fields of that single context, and completion-based caching (`formulaArgCache`/`calcRawCache`) only ever stores results of evaluations that *finish*.\n\nDuring a pure cycle no nested evaluation ever finishes, so nothing is ever cached to break the recursion, and each hop re-arms the entire budget. Two ordinary, Excel-legal constructs in an attacker-supplied workbook are enough:\n\n- `A1` (dynamic array formula, ref `A1:A1`): `_xlfn.ANCHORARRAY($B$1)`\n- `B1` (dynamic array formula, ref `B1:B1`): `_xlfn.ANCHORARRAY($A$1)`\n\n\u2192 `CalcCellValue \u2192 calcCellValue \u2192 evalInfixExp \u2192 parseReference \u2192 cellResolver \u2192 \u2026 \u2192 ANCHORARRAY \u2192 CalcCellValue \u2192 \u2026` forever, ending in a **fatal, unrecoverable** Go runtime error: `runtime: goroutine stack exceeds \u2026-byte limit / fatal error: stack overflow`. Go stack overflows cannot be recovered \u2014 the whole process aborts.\n\n### Details\n\n- The terminating edge the iterations gate is supposed to provide does not exist across contexts: there is no in-flight tracking shared between nested `CalcCellValue` calls.\n- Both formulas are ordinary Excel-legal constructs; no exotic XML is required.\n- Excelize\u0027s own APIs reach formula evaluation on untrusted cells implicitly (e.g. `pivotTable.go:538`, `picture.go:985/1141`, `col.go:892`), so a service that merely adds a pivot table or a picture over such a workbook dies.\n- No option value prevents it: `MaxCalcIterations` is irrelevant because every hop gets a fresh budget.\n- Measured: a 64 MB stack budget is exhausted in ~0.09 s; the ~1 GB default in ~1\u20132 s.\n\n### PoC\n\nA standalone program (public API only) was provided to the maintainer by email (`4-anchorarray-recursion`): `NewFile` + `SetCellFormula` with `FormulaOpts{Type: array, Ref: A1:A1 / B1:B1}`, then `CalcCellValue(\"Sheet1\",\"A1\")`. On master `ecd99d761fe0` (2026-09-08) the process aborts with `fatal error: stack overflow`; with the proposed patch the cycle terminates normally (`CYCLE_TERMINATED`) and existing calc tests pass.\n\n### Impact\n\nAn attacker ships a workbook containing the two formulas; any service that evaluates a formula over those cells \u2014 directly via `CalcCellValue`, or implicitly via `AddPivotTable` / `AddPicture` / auto-fit \u2014 aborts. Remote, unauthenticated, process-fatal, no configuration prevents it.\n\n### Proposed fix\n\nEvaluate spill-range cells through the **current** calculation context \u2014 `fn.f.cellResolver(fn.ctx, \u2026)` instead of the exported `CalcCellValue` \u2014 so the entry check and iterations gate of the running calculation apply. `cellResolver` returns the typed value directly (dropping a string round-trip); an `ArgEmpty \u2192 \"\"` shim preserves the existing `ToNumber` behavior for empty spill cells, and a fresh-context fallback covers the legacy nil-ctx test paths. A complete patch has been provided to the maintainer.",
  "id": "GHSA-wp2g-vpjj-g53r",
  "modified": "2026-10-08T16:31:21Z",
  "published": "2026-10-08T16:31:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/qax-os/excelize/security/advisories/GHSA-wp2g-vpjj-g53r"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-107216"
    },
    {
      "type": "WEB",
      "url": "https://github.com/qax-os/excelize/commit/ea12859e43c64d498ecf839263c5f917391f3316"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/qax-os/excelize"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Excelize ANCHORARRAY: mutually-referencing array formulas recurse unboundedly via re-entrant CalcCellValue, causing a fatal stack overflow"
}

CVE-2026-107216 (GCVE-0-2026-107216)

Vulnerability from cvelistv5 – Published: 2026-10-07 17:51 – Updated: 2026-10-07 18:51

Title

Excelize ANCHORARRAY: mutually-referencing array formulas recurse unboundedly via re-entrant CalcCellValue, causing a fatal stack overflow

Summary

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.8.1 to 2.11.0, ANCHORARRAY recursively calls the exported CalcCellValue function, creating a fresh calculation context at each cycle and bypassing in-flight and iteration controls. ANCHORARRAY calls CalcCellValue instead of cellResolver, so each recursive hop receives a new calcContext and loses cycle state. When mutually referencing dynamic-array formulas are evaluated directly or through formula-evaluating APIs, each recursion hop resets the cycle budget and prevents completion-based caches from breaking the cycle, allowing an attacker to cause a fatal Go stack overflow and abort the process. No fixed version is available as of this review.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-07 18:50 UTC

CWE

CWE-674 - Uncontrolled Recursion

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7642 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/qax-os/excelize/security/advis…	x_refsource_CONFIRM
https://github.com/qax-os/excelize/commit/ea12859…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
qax-os	excelize	Affected: >= 2.8.1, <= 2.11.0

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-107216",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-07T18:50:55.568606Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        "providerMetadata": {
          "dateUpdated": "2026-10-07T18:51:04.748Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "excelize",
          "vendor": "qax-os",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.8.1, \u003c= 2.11.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.8.1 to 2.11.0, ANCHORARRAY recursively calls the exported CalcCellValue function, creating a fresh calculation context at each cycle and bypassing in-flight and iteration controls. ANCHORARRAY calls CalcCellValue instead of cellResolver, so each recursive hop receives a new calcContext and loses cycle state. When mutually referencing dynamic-array formulas are evaluated directly or through formula-evaluating APIs, each recursion hop resets the cycle budget and prevents completion-based caches from breaking the cycle, allowing an attacker to cause a fatal Go stack overflow and abort the process. No fixed version is available as of this review."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-674",
              "description": "CWE-674: Uncontrolled Recursion",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-07T17:51:31.980Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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      },
      "references": [
        {
          "name": "https://github.com/qax-os/excelize/security/advisories/GHSA-wp2g-vpjj-g53r",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/qax-os/excelize/security/advisories/GHSA-wp2g-vpjj-g53r"
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      "source": {
        "advisory": "GHSA-wp2g-vpjj-g53r",
        "discovery": "UNKNOWN"
      },
      "title": "Excelize ANCHORARRAY: mutually-referencing array formulas recurse unboundedly via re-entrant CalcCellValue, causing a fatal stack overflow"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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    "datePublished": "2026-10-07T17:51:31.980Z",
    "dateReserved": "2026-10-07T14:34:14.815Z",
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    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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Action not permitted

GHSA-WP2G-VPJJ-G53R

Summary

Details

PoC

Impact

Proposed fix

CVE-2026-107216 (GCVE-0-2026-107216)

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