CVE-2026-62999

Copier: Percent-encoded dot segments in template URLs can allow trusted-prefix escape (Incomplete fix for trust-prefix bypass)

Published Jul 31, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Copier is a library and CLI app for rendering project templates. From 9.5.0 through 9.16.0, percent-encoded parent-directory segments or encoded path separators in a template URL can match a configured trusted repository prefix before an HTTP server or Git transport decodes the path, allowing unsafe template features from a repository outside the trusted prefix to run after user interaction. This issue is fixed in version 9.17.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Copier-org
Copier-org copier
Vendors & Products Copier-org
Copier-org copier
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Copier is a library and CLI app for rendering project templates. From 9.5.0 through 9.16.0, percent-encoded parent-directory segments or encoded path separators in a template URL can match a configured trusted repository prefix before an HTTP server or Git transport decodes the path, allowing unsafe template features from a repository outside the trusted prefix to run after user interaction. This issue is fixed in version 9.17.0.
Title Copier: Percent-encoded dot segments in template URLs can allow trusted-prefix escape (Incomplete fix for trust-prefix bypass)
Weaknesses CWE-180
CWE-22
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 31, 2026, 7:59 PM
Reserved
Jul 14, 2026, 11:10 PM
Status
Deferred
Published
Jul 31, 2026, 8:16 PM
Modified
Oct 23, 2026, 11:10 PM