ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow

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  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-2069",
    "assignerOrgId": "1af790b2-7ee1-4545-860a-a788eba489b5",
    "assignerShortName": "VulDB",
    "dateUpdated": "2026-02-06T22:02:08.933Z",
    "dateReserved": "2026-02-06T07:41:07.150Z",
    "datePublished": "2026-02-06T22:02:08.933Z",
    "state": "PUBLISHED"
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        "dateUpdated": "2026-02-06T22:02:08.933Z"
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      "title": "ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow",
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw has been found in ggml-org llama.cpp up to 55abc39. Impacted is the function llama_grammar_advance_stack of the file llama.cpp/src/llama-grammar.cpp of the component GBNF Grammar Handler. This manipulation causes stack-based buffer overflow. The attack needs to be launched locally. The exploit has been published and may be used. Patch name: 18993. To fix this issue, it is recommended to deploy a patch."
        }
      ],
      "affected": [
        {
          "vendor": "ggml-org",
          "product": "llama.cpp",
          "modules": [
            "GBNF Grammar Handler"
          ],
          "versions": [
            {
              "version": "55abc39",
              "status": "affected"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "Stack-based Buffer Overflow",
              "cweId": "CWE-121",
              "type": "CWE"
            }
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        {
          "descriptions": [
            {
              "lang": "en",
              "description": "Memory Corruption",
              "cweId": "CWE-119",
              "type": "CWE"
            }
          ]
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      ],
      "references": [
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          "url": "https://vuldb.com/?id.344636",
          "name": "VDB-344636 | ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow",
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        },
        {
          "url": "https://vuldb.com/?submit.745263",
          "name": "Submit #745263 | llama.cpp commit 55abc39 Stack-based Buffer Overflow",
          "tags": [
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        },
        {
          "url": "https://github.com/ggml-org/llama.cpp/issues/18988",
          "tags": [
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        {
          "url": "https://github.com/ggml-org/llama.cpp/issues/18988#event-4426704865",
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        {
          "url": "https://github.com/user-attachments/files/24761101/poc.zip",
          "tags": [
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        {
          "url": "https://github.com/ggml-org/llama.cpp/pull/18993",
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        {
          "url": "https://github.com/ggml-org/llama.cpp/",
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            "product"
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          "time": "2026-02-06T00:00:00.000Z",
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