Vulnerability · Published Jul 31, 2026 · Assigned by GitHub_M

CVE-2026-62999Copier: Percent-encoded dot segments in template URLs can allow trusted-prefix escape (Incomplete fix for trust-prefix bypass)

High 7.5

In plain English

A high-severity path traversal in copier from copier-org. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 61.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
copier-org	copier	>= 9.5.0, <= 9.16.0

Weakness: CWE-22, CWE-180 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References

https://github.com/copier-org/copier/security/advisories/GHSA-34mv-rjq9-5mch x_refsource_CONFIRM
https://github.com/copier-org/copier/commit/7408f0d6287a7bf452715fd9f25dc54eaba3c295 x_refsource_MISC
https://github.com/copier-org/copier/releases/tag/v9.17.0 x_refsource_MISC