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skilo add follows symbolic links, allowing arbitrary local file disclosure from a malicious skill source

Moderate severity GitHub Reviewed Published Jun 8, 2026 in manuelmauro/skilo • Updated Jul 28, 2026

Package

cargo skilo (Rust)

Affected versions

>= 0.5.0, < 0.11.1

Patched versions

0.11.1

Description

Impact

skilo add installs a skill by recursively copying the skill directory into the
target skills directory. The copy routine (copy_dir_all) classified each entry
with std::fs::DirEntry::file_type() — which does not follow symlinks — and
then copied non-directory entries with std::fs::copy(), which does
dereference symlinks.

As a result, a skill containing a symbolic link such as
reference.txt -> /home/<user>/.ssh/id_rsa was copied as a regular file whose
contents are the link's target. A malicious skill source — for example a git
repository installed via skilo add github.com/<attacker>/<skills>, or a local
path — could read arbitrary files readable by the user running skilo add (SSH
keys, cloud credentials, .env files, etc.) and place their contents inside the
installed skill directory, where the user or their agent may later read, share,
or sync them.

This is arbitrary local file disclosure (CWE-59 / CWE-61, symlink following)
triggered by installing an untrusted skills source.

Patches

Fixed in 0.11.1. copy_dir_all now rejects symbolic-link entries at any
recursion depth (failing closed with a dedicated error) instead of dereferencing
them.

Workarounds

  • Only install skills from sources you trust.
  • Inspect a skill source for symbolic links before running skilo add.

Affected versions

Introduced together with the skilo add command in 0.5.0 and present through
0.11.0. Releases before 0.5.0 do not include the add command.

References

@manuelmauro manuelmauro published to manuelmauro/skilo Jun 8, 2026
Published to the GitHub Advisory Database Jul 28, 2026
Reviewed Jul 28, 2026
Last updated Jul 28, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS score

Weaknesses

Improper Link Resolution Before File Access ('Link Following')

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. Learn more on MITRE.

UNIX Symbolic Link (Symlink) Following

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-6xx4-9wp6-65p7

Source code

Credits

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