Heap Overflow in Vim

Vim is an open source, command line text editor. Prior to version 9.1.2132, a heap buffer overflow vulnerability exists in Vim's tag file resolution logic when processing the 'helpfile' option. The vulnerability is located in the get_tagfname() function in src/tag.c. When processing help file tags, Vim copies the user-controlled 'helpfile' option value into a fixed-size heap buffer of MAXPATHL + 1 bytes (typically 4097 bytes) using an unsafe STRCPY() operation without any bounds checking. This issue has been patched in version 9.1.2132.

Problem type

CWE-122: Heap-based Buffer Overflow

Affected products

vim

vim

< 9.1.2132 - AFFECTED

References

https://github.com/vim/vim/security/advisories/GHSA-5w93-4g67-mm43

https://github.com/vim/vim/security/advisories/GHSA-5w93-4g67-mm43

x_refsource_CONFIRM

https://github.com/vim/vim/commit/0714b15940b245108e6e9d7aa2260dd849a26fa9

https://github.com/vim/vim/commit/0714b15940b245108e6e9d7aa2260dd849a26fa9

x_refsource_MISC

https://github.com/vim/vim/releases/tag/v9.1.2132

https://github.com/vim/vim/releases/tag/v9.1.2132

x_refsource_MISC

JSON source

https://cveawg.mitre.org/api/cve/CVE-2026-25749

Click to expand

{
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  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-25749",
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "dateUpdated": "2026-02-06T22:43:38.630Z",
    "dateReserved": "2026-02-05T18:35:52.356Z",
    "datePublished": "2026-02-06T22:43:38.630Z",
    "state": "PUBLISHED"
  },
  "containers": {
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        "shortName": "GitHub_M",
        "dateUpdated": "2026-02-06T22:43:38.630Z"
      },
      "title": "Heap Overflow in Vim",
      "descriptions": [
        {
          "lang": "en",
          "value": "Vim is an open source, command line text editor. Prior to version 9.1.2132, a heap buffer overflow vulnerability exists in Vim's tag file resolution logic when processing the 'helpfile' option. The vulnerability is located in the get_tagfname() function in src/tag.c. When processing help file tags, Vim copies the user-controlled 'helpfile' option value into a fixed-size heap buffer of MAXPATHL + 1 bytes (typically 4097 bytes) using an unsafe STRCPY() operation without any bounds checking. This issue has been patched in version 9.1.2132."
        }
      ],
      "affected": [
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          "vendor": "vim",
          "product": "vim",
          "versions": [
            {
              "version": "< 9.1.2132",
              "status": "affected"
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      "problemTypes": [
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          "descriptions": [
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              "lang": "en",
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      "references": [
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          "tags": [
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          "tags": [
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        },
        {
          "url": "https://github.com/vim/vim/releases/tag/v9.1.2132",
          "name": "https://github.com/vim/vim/releases/tag/v9.1.2132",
          "tags": [
            "x_refsource_MISC"
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      "metrics": [
        {
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H",
            "attackVector": "LOCAL",
            "attackComplexity": "LOW",
            "privilegesRequired": "LOW",
            "userInteraction": "REQUIRED",
            "scope": "UNCHANGED",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "availabilityImpact": "HIGH",
            "baseScore": 6.6,
            "baseSeverity": "MEDIUM"
          }
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    }
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}