Nixpkgs security tracker

Permalink CVE-2026-53951

8.8 HIGH

CVSS version (CVSS): 4.0
Attack Vector (AV): Local (L)
Attack Complexity (AC): Low (L)
Attack Requirement (AT): Present (P)
Privileges Required (PR): None (N)
User Interaction (UI): Passive (P)
Vulnerable System Impact Confidentiality (VC): High (H)
Vulnerable System Impact Integrity (VI): High (H)
Vulnerable System Impact Availability (VA): High (H)
Subsequent System Impact Confidentiality (SC): High (H)
Subsequent System Impact Integrity (SI): High (H)
Subsequent System Impact Availability (SA): High (H)
Modified Attack Vector (MAV): Local (L)
Modified Attack Complexity (MAC): Low (L)
Modified Attack Requirement (MAT): Present (P)
Modified Privileges Required (MPR): None (N)
Modified User Interaction (MUI): Passive (P)
Modified Vulnerable System Impact Confidentiality (MVC): High (H)
Modified Vulnerable System Impact Integrity (MVI): High (H)
Modified Vulnerable System Impact Availability (MVA): High (H)
Modified Subsequent System Impact Confidentiality (MSC): High (H)
Modified Subsequent System Impact Integrity (MSI): High (H)
Modified Subsequent System Impact Availability (MSA): High (H)
Safety (S): Not Defined (X)
Automatable (AU): Not Defined (X)
Recovery (R): Not Defined (X)
Value Density (V): Not Defined (X)
Vulnerability Response Effort (RE): Not Defined (X)
Provider Urgency (U): Not Defined (X)
Confidentiality Req. (CR): Not Defined (X)
Integrity Req. (IR): Not Defined (X)
Availability Req. (AR): Not Defined (X)
Exploit Maturity (E): Not Defined (X)

created 1 week, 1 day ago Activity log

Created suggestion 1 week, 1 day ago

Copier: trust-prefix bypass via path traversal runs tasks unprompted

Copier is a library and CLI app for rendering project templates. In versions 9.5.0 through 9.15.1, the `trust` setting's prefix match (`copier/_settings.py`) compares the template URL against a trusted prefix with a raw `str.startswith` and no path normalization, while the URL is normalized when the template is actually fetched (`Path.resolve()` for local paths; libcurl dot-segment removal for `https`). A template reference that textually starts with a trusted prefix but contains `..` is therefore granted trust yet resolves to a different, attacker-controlled template, whose `tasks` / `migrations` / `jinja_extensions` then run without the `--trust` prompt — arbitrary command execution. Version 9.15.2 patches the issue.