GHSA-9FFQ-6457-8958
Vulnerability from github – Published: 2026-03-25 20:01 – Updated: 2026-03-27 21:36Summary
A path traversal vulnerability exists in the FileUtil class of the code16/sharp package. The application fails to sanitize file extensions properly, allowing path separators to be passed into the storage layer.
Detail
In src/Utils/FileUtil.php, the FileUtil::explodeExtension() function extracts a file's extension by splitting the filename at the last dot. However, the extracted extension is never sanitized. While the application uses a normalizeName() function, this function only cleans the base filename, meaning any path separators (such as /) injected into the extension will survive and be passed into the storeAs() function.
Impact
Exploiting this flaw allows an authenticated attacker to manipulate file paths: - Files can be written outside of the intended tmp directory via path traversal. For more details on the package, visit: https://github.com/code16/sharp - Existing critical files (such as .env or configuration files) could potentially be overwritten. Review the CWE definition here: https://cwe.mitre.org/data/definitions/22.html (Note: This vulnerability was successfully chained with CWE-434 in a local Proof of Concept to confirm the traversal.)
Patches
This issue has been patched by properly sanitizing the extension using pathinfo(PATHINFO_EXTENSION) instead of strrpos(), alongside applying strict regex replacements to both the base name and the extension. The fix is available in pull request #715
Credits
Reported by zaurgsynv.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "code16/sharp"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "9.20.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33686"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-25T20:01:04Z",
"nvd_published_at": "2026-03-26T22:16:31Z",
"severity": "HIGH"
},
"details": "### Summary\nA path traversal vulnerability exists in the FileUtil class of the code16/sharp package. The application fails to sanitize file extensions properly, allowing path separators to be passed into the storage layer.\n\n### Detail\nIn `src/Utils/FileUtil.php`, the `FileUtil::explodeExtension()` function extracts a file\u0027s extension by splitting the filename at the last dot. However, the extracted extension is never sanitized. While the application uses a `normalizeName()` function, this function only cleans the base filename, meaning any path separators (such as /) injected into the extension will survive and be passed into the `storeAs()` function.\n\n### Impact\nExploiting this flaw allows an authenticated attacker to manipulate file paths:\n- Files can be written outside of the intended tmp directory via path traversal. For more details on the package, visit: https://github.com/code16/sharp\n- Existing critical files (such as .env or configuration files) could potentially be overwritten. Review the CWE definition here: https://cwe.mitre.org/data/definitions/22.html (Note: This vulnerability was successfully chained with CWE-434 in a local Proof of Concept to confirm the traversal.)\n\n### Patches\nThis issue has been patched by properly sanitizing the extension using `pathinfo(PATHINFO_EXTENSION)` instead of `strrpos()`, alongside applying strict regex replacements to both the base name and the extension. The fix is available in pull request #715\n\n### Credits\nReported by [zaurgsynv](https://github.com/zaurgsynv).",
"id": "GHSA-9ffq-6457-8958",
"modified": "2026-03-27T21:36:04Z",
"published": "2026-03-25T20:01:04Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/code16/sharp/security/advisories/GHSA-9ffq-6457-8958"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33686"
},
{
"type": "WEB",
"url": "https://github.com/code16/sharp/pull/715"
},
{
"type": "PACKAGE",
"url": "https://github.com/code16/sharp"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Sharp is Vulnerable to Path Traversal via Unsanitized Extension in FileUtil"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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