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CVE-2026-41992

Full vulnerability record from the local CVENow database.

Description

GNU gzip contains a global buffer overflow vulnerability in the LZH decompression logic caused by improper reuse of shared global state between different decompression formats within a single execution. GNU gzip maintains a global array that is shared across the LZ77, LZW, and LZH decompression routines and is not reinitialized between files processed in the same invocation. By decompressing a specially crafted LZW file followed by a specially crafted LZH file in a single gzip -d command, an attacker can poison the shared global state and subsequently trigger an out‑of‑bounds read in the LZH decoder. The LZH decompression logic follows stale values left in the shared array, causing reads past the end of the allocated global buffer. This issue has been fixed in commits 63dbf6b3b9e6e781df1a6a64e609b10e23969681 and e7378c2d421be6a286922374425680bbe9ad8b7d.

Severity
MEDIUM
CVSS score
6.9 (v4.0)
Vulnerability status
Modified
Source identifier
[email protected]
Published
2026-06-29 12:16:29.940000
Last modified
2026-10-25 21:10:00.770000
View original CVE JSON 
{
  "id": "CVE-2026-41992",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-29T12:16:29.940",
  "lastModified": "2026-10-25T21:10:00.770",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "GNU gzip contains a global buffer overflow vulnerability in the LZH decompression logic caused by improper reuse of shared global state between different decompression formats within a single execution. GNU gzip maintains a global array that is shared across the LZ77, LZW, and LZH decompression routines and is not reinitialized between files processed in the same invocation.\nBy decompressing a specially crafted LZW file followed by a specially crafted LZH file in a single gzip -d command, an attacker can poison the shared global state and subsequently trigger an out‑of‑bounds read in the LZH decoder. The LZH decompression logic follows stale values left in the shared array, causing reads past the end of the allocated global buffer.\n\nThis issue has been fixed in commits 63dbf6b3b9e6e781df1a6a64e609b10e23969681 and e7378c2d421be6a286922374425680bbe9ad8b7d."
    },
    {
      "lang": "es",
      "value": "GNU gzip contiene una vulnerabilidad global de desbordamiento de búfer en la lógica de descompresión LZH causada por la reutilización inadecuada de un estado global compartido entre diferentes formatos de descompresión dentro de una única ejecución. GNU gzip mantiene una matriz global que se comparte entre las rutinas de descompresión LZ77, LZW y LZH y no se reinicializa entre archivos procesados en la misma invocación.\nAl descomprimir un archivo LZW especialmente diseñado seguido de un archivo LZH especialmente diseñado en un único comando gzip -d, un atacante puede envenenar el estado global compartido y posteriormente desencadenar una lectura fuera de límites en el decodificador LZH. La lógica de descompresión LZH sigue valores obsoletos dejados en la matriz compartida, causando lecturas más allá del final del búfer global asignado.\n\nEste problema ha sido solucionado en el commit 63dbf6b3b9e6e781df1a6a64e609b10e23969681"
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "GNU",
          "product": "gzip",
          "defaultStatus": "unaffected",
          "modules": [
            "unlzh.c (LZH decompressor)",
            "unlzw.c (LZW decompressor)",
            "gzip.c (shared global state)"
          ],
          "repo": "https://cgit.git.savannah.gnu.org/cgit/gzip.git/",
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "1.14",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
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        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
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          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
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          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-06-29T13:30:31.933225Z",
          "id": "CVE-2026-41992",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-126"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:gnu:gzip:*:*:*:*:*:*:*:*",
              "versionEndIncluding": "1.14",
              "matchCriteriaId": "FA344ACC-4D0B-42F2-BED0-04561F842EA1"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://cert.pl/en/posts/2026/04/CVE-2026-41991/",
      "source": "[email protected]",
      "tags": [
        "Broken Link"
      ]
    },
    {
      "url": "https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=63dbf6b3b9e6e781df1a6a64e609b10e23969681",
      "source": "[email protected]",
      "tags": [
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    {
      "url": "https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=e7378c2d421be6a286922374425680bbe9ad8b7d",
      "source": "[email protected]"
    },
    {
      "url": "https://www.gnu.org/software/gzip/",
      "source": "[email protected]",
      "tags": [
        "Product"
      ]
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/08/23/1",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/08/25/1",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
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    {
      "url": "http://www.openwall.com/lists/oss-security/2026/08/27/2",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
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}