CVE-2026-23986

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Source
https://cve.org/CVERecord?id=CVE-2026-23986
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23986.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-23986
Aliases
Published
2026-01-21T22:20:37Z
Modified
2026-10-21T02:30:25Z
Severity
  • 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Copier safe template has arbitrary filesystem write access via directory symlinks when _preserve_symlinks: true
Details

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 write to arbitrary directories outside the destination path by using directory a symlink along with _preserve_symlinks: true and a generated directory structure whose rendered path is inside the symlinked directory. This way, a malicious template author can create a template that overwrites arbitrary files (according to the user's write permissions), e.g., to cause havoc. Version 9.11.2 patches the issue.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-61"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23986.json"
}
References

Affected packages

Git / github.com/copier-org/copier

Affected ranges

Type
GIT
Repo
https://github.com/copier-org/copier
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
b9ee2962b5e0a81b838261b630bd36d0c6c3fa87
Fixed
b3a7b3772d17cf0e7a4481978188c9f536c8d8f6
Database specific
Show details 
{
    "extracted_events":  [
        {
            "cpe":  "cpe:2.3:a:copier-org:copier:*:*:*:*:*:python:*:*",
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "9.11.2"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "range":  [
                {
                    "fixed":  "b3a7b3772d17cf0e7a4481978188c9f536c8d8f6"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v9.11.2",
            "range":  [
                {
                    "fixed":  "b9ee2962b5e0a81b838261b630bd36d0c6c3fa87"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

1.*
1.1.1
3.*
3.0.0-alpha5
3.0.0-alpha6
v2.*
v2.2.3
v2.3
v2.3.1
v2.3.2
v2.3.3
v2.4.0
v2.4.1
v2.4.2
v2.5.0
v2.5.1
v3.*
v3.0.0
v3.0.0-alpha1
v3.0.0-alpha2
v3.0.0-alpha3
v3.0.0-alpha4
v3.0.0-alpha7
v3.0.0-alpha8
v3.0.0-beta1
v3.0.1
v3.0.2
v3.0.3
v3.0.4
v3.0.5
v3.0.6
v3.1.0
v3.2.0
v4.*
v4.0.0
v4.0.1
v4.0.2
v4.1.0
v5.*
v5.0.0
v5.1.0
v6.*
v6.0.0
v6.0.0a0
v6.0.0a1
v6.0.0a2
v6.0.0a3
v6.0.0a4
v6.0.0a5
v6.0.0a6
v6.0.0a7
v6.0.0a8
v6.0.0a9
v6.0.0b0
v6.1.0
v6.2.0
v7.*
v7.0.1
v7.1.0
v7.1.0a0
v7.2.0
v8.*
v8.0.0
v8.1.0
v8.2.0
v8.3.0
v9.*
v9.0.0
v9.0.1
v9.1.1
v9.10.0
v9.10.1
v9.10.2
v9.10.3
v9.11.0
v9.11.1
v9.2.0
v9.3.0
v9.3.1
v9.4.0
v9.4.1
v9.5.0
v9.6.0
v9.7.0
v9.7.1
v9.8.0
v9.9.0
v9.9.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23986.json"