CVE-2026-23968 json
Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false
published 9mo ago modified 4mo ago also GHSA-xjhm-gp88-8pfx , PYSEC-2026-1274 , EUVD-2026-4142
- cvss
- 5.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 15%
- public exploits
- 0
- none known
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.
Patch / fix
Is CVE-2026-23968 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 9mo ago
Exploit prediction
0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- github.com https://github.com/copier-org/copier/security/advisories/GHSA-xjhm-gp88-8pfx referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.8 | 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 |
| CNA | 4.0 | 6.8 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| GitHub | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| OSV | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | copier | <9.11.2 |
9.11.2 |
Affected products
- copier-org copier
Classification
- Weakness
-
- CWE-61 UNIX Symbolic Link (Symlink) Following
References
-
github.com
/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6
web, patch
-
github.com
/copier-org/copier/security/advisories/GHSA-xjhm-gp88-8pfx
web, exploit, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-23968
advisory
-
github.com
/copier-org/copier
package
-
pypi.org
/project/copier
package
-
github.com
/advisories/GHSA-xjhm-gp88-8pfx
advisory
Sources
- CVE List CVE-2026-23968
- GitHub Advisory GHSA-xjhm-gp88-8pfx
- NVD CVE-2026-23968
- OSV PYSEC-2026-1274
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.