Vulnerability-Lookup

ubuntu-cve-2026-5917

Vulnerability from osv_ubuntu

Published

2026-08-11 22:17

Modified

2026-09-02 16:11

Summary

Details

libgit2 versions before 1.8.7 and 1.9.0 before 1.9.7 built with the libssh2 SSH backend (USE_SSH=libssh2) contain a shell command injection vulnerability that allows remote attackers to execute arbitrary commands on an SSH server by supplying a repository path containing unescaped shell metacharacters such as single quotes, semicolons, or pipes. The gen_proto() function in ssh_libssh2.c inserts the repository path directly into a shell command string without escaping special characters before passing it to libssh2_channel_exec(), enabling an attacker to craft a malicious submodule URL in a .gitmodules file that, when processed during a recursive clone, causes the remote server's shell to interpret injected commands under the victim's SSH user account.

Severity

8.8 (High)


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

8.6 (High)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-5917	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-5917	REPORT
	https://github.com/libgit2/libgit2	REPORT
	https://www.vulncheck.com/advisories/libgit2-shel…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libgit2-0",
            "binary_version": "0.19.0-2ubuntu0.4+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@0.19.0-2ubuntu0.4+esm2?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.19.0-2",
        "0.19.0-2ubuntu0.4",
        "0.19.0-2ubuntu0.4+esm1",
        "0.19.0-2ubuntu0.4+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libgit2-24",
            "binary_version": "0.24.1-2ubuntu0.2+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@0.24.1-2ubuntu0.2+esm3?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.22.2-2",
        "0.23.1-1",
        "0.24.1-2",
        "0.24.1-2ubuntu0.2",
        "0.24.1-2ubuntu0.2+esm1",
        "0.24.1-2ubuntu0.2+esm2",
        "0.24.1-2ubuntu0.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libgit2-26",
            "binary_version": "0.26.0+dfsg.1-1.1ubuntu0.2+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@0.26.0+dfsg.1-1.1ubuntu0.2+esm2?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.25.1+really0.24.6-1",
        "0.26.0+dfsg.1-1.1",
        "0.26.0+dfsg.1-1.1build1",
        "0.26.0+dfsg.1-1.1ubuntu0.2",
        "0.26.0+dfsg.1-1.1ubuntu0.2+esm1",
        "0.26.0+dfsg.1-1.1ubuntu0.2+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libgit2-28",
            "binary_version": "0.28.4+dfsg.1-2ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@0.28.4+dfsg.1-2ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.27.7+dfsg.1-0.2build1",
        "0.28.3+dfsg.1-1",
        "0.28.3+dfsg.1-1ubuntu1",
        "0.28.4+dfsg.1-2",
        "0.28.4+dfsg.1-2ubuntu0.1",
        "0.28.4+dfsg.1-2ubuntu0.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libgit2-1.1",
            "binary_version": "1.1.0+dfsg.1-4.1ubuntu0.1+esm1"
          },
          {
            "binary_name": "libgit2-fixtures",
            "binary_version": "1.1.0+dfsg.1-4.1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@1.1.0+dfsg.1-4.1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.1.0+dfsg.1-4",
        "1.1.0+dfsg.1-4.1",
        "1.1.0+dfsg.1-4.1build1",
        "1.1.0+dfsg.1-4.1ubuntu0.1",
        "1.1.0+dfsg.1-4.1ubuntu0.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libgit2-1.7",
            "binary_version": "1.7.2+ds-1ubuntu3.1"
          },
          {
            "binary_name": "libgit2-fixtures",
            "binary_version": "1.7.2+ds-1ubuntu3.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@1.7.2+ds-1ubuntu3.1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.1+ds-1ubuntu1",
        "1.7.1+ds-2ubuntu1",
        "1.7.2+ds-1ubuntu1",
        "1.7.2+ds-1ubuntu2",
        "1.7.2+ds-1ubuntu3",
        "1.7.2+ds-1ubuntu3.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libgit2-1.9",
            "binary_version": "1.9.1+ds-1ubuntu1.1"
          },
          {
            "binary_name": "libgit2-fixtures",
            "binary_version": "1.9.1+ds-1ubuntu1.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libgit2",
        "purl": "pkg:deb/ubuntu/libgit2@1.9.1+ds-1ubuntu1.1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9.0+ds-2ubuntu2",
        "1.9.1+ds-1ubuntu1",
        "1.9.1+ds-1ubuntu1.1"
      ]
    }
  ],
  "aliases": [],
  "details": "libgit2 versions before 1.8.7 and 1.9.0 before 1.9.7 built with the libssh2 SSH backend (USE_SSH=libssh2) contain a shell command injection vulnerability that allows remote attackers to execute arbitrary commands on an SSH server by supplying a repository path containing unescaped shell metacharacters such as single quotes, semicolons, or pipes. The gen_proto() function in ssh_libssh2.c inserts the repository path directly into a shell command string without escaping special characters before passing it to libssh2_channel_exec(), enabling an attacker to craft a malicious submodule URL in a .gitmodules file that, when processed during a recursive clone, causes the remote server\u0027s shell to interpret injected commands under the victim\u0027s SSH user account.",
  "id": "UBUNTU-CVE-2026-5917",
  "modified": "2026-09-02T16:11:55Z",
  "published": "2026-08-11T22:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-5917"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-5917"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libgit2/libgit2"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/libgit2-shell-command-injection-via-ssh-libssh2-backend"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-5917"
  ]
}

CVE-2026-5917 (GCVE-0-2026-5917)

Vulnerability from cvelistv5 – Published: 2026-08-11 21:40 – Updated: 2026-08-26 16:48 X_Open Source

Title

libgit2 Shell Command Injection via ssh_libssh2 Backend

Summary

Severity

8.6 (High)


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

8.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-12 12:48 UTC

CWE

CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Assigner

VulnCheck mitre root

References

2 references

URL	Tags
https://github.com/libgit2/libgit2/security/advis…	vendor-advisorypatch
https://www.vulncheck.com/advisories/libgit2-shel…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
libgit2	libgit2	Affected: 0 , < 1.8.7 (custom) Affected: 1.9.0 , < 1.9.7 (semver)

Date Public

2026-08-11 00:00

Credits

Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc. Isabel Mill

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-5917",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-12T12:48:11.019321Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-12T12:48:30.674Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "libgit2",
          "vendor": "libgit2",
          "versions": [
            {
              "lessThan": "1.8.7",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            },
            {
              "lessThan": "1.9.7",
              "status": "affected",
              "version": "1.9.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc."
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Isabel Mill"
        }
      ],
      "datePublic": "2026-08-11T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "libgit2 versions before 1.8.7 and 1.9.0 before 1.9.7 built with the libssh2 SSH backend (USE_SSH=libssh2) contain a shell command injection vulnerability that allows remote attackers to execute arbitrary commands on an SSH server by supplying a repository path containing unescaped shell metacharacters such as single quotes, semicolons, or pipes. The gen_proto() function in ssh_libssh2.c inserts the repository path directly into a shell command string without escaping special characters before passing it to libssh2_channel_exec(), enabling an attacker to craft a malicious submodule URL in a .gitmodules file that, when processed during a recursive clone, causes the remote server\u0027s shell to interpret injected commands under the victim\u0027s SSH user account."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.6,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "ACTIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
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          ]
        },
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          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-78",
              "description": "Improper Neutralization of Special Elements used in an OS Command (\u0027OS Command Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-26T16:48:52.924Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
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      },
      "references": [
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          "tags": [
            "vendor-advisory",
            "patch"
          ],
          "url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-xqj4-2j5v-rr75"
        },
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/libgit2-shell-command-injection-via-ssh-libssh2-backend"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "tags": [
        "x_open-source"
      ],
      "title": "libgit2 Shell Command Injection via ssh_libssh2 Backend",
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        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-5917",
    "datePublished": "2026-08-11T21:40:29.078Z",
    "dateReserved": "2026-04-08T20:02:31.343Z",
    "dateUpdated": "2026-08-26T16:48:52.924Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.