How severe is CVE-2026-33687?

CVE-2026-33687 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-33687?

CVE-2026-33687 affects the following packages: code16/sharp (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2026-33687?

Update code16/sharp to 9.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33687 is resolved across your whole dependency graph.

How do I detect CVE-2026-33687 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code16/sharp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-33687 if there is no patch (or I can't update yet)?

Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.

Is CVE-2026-33687 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-33687 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-33687?

CVE-2026-33687 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 45th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-33687?

CVE-2026-33687 is classified as Unrestricted File Upload (CWE-434). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-33687 published, and has it been updated?

CVE-2026-33687 was published on March 26, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

HIGH severity

CVE-2026-33687 — sharp

HIGHFix: code16/sharp#714

CVE-2026-33687 is a high-severity (CVSS 8.8) Unrestricted File Upload vulnerability in code16/sharp. A fix is available for code16/sharp — see the affected versions and patch details below.

Sharp has Unrestricted File Upload via Client-Controlled Validation Rules

Also known asGHSA-fr76-5637-w3g9

Published

Mar 26, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33687.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs45th percentile — riskier than 45% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐘code16/sharp

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The code16/sharp Laravel admin panel package contains a vulnerability in its file upload endpoint that allows authenticated users to bypass all file type restrictions.

Details

The upload endpoint within the ApiFormUploadController accepts a client-controlled validation_rule parameter. This parameter is directly passed into the Laravel validator without sufficient server-side enforcement. By intercepting the request and sending validation_rule[]=file, an attacker can completely bypass all MIME type and file extension restrictions. The vulnerable code is located in src/Http/Controllers/Api/ApiFormUploadController.php at line 24.

Impact

This vulnerability leads to several critical security risks:

Attackers can upload arbitrary files, including PHP webshells, to the server. For more details on the package, visit: https://github.com/code16/sharp

MIME type and extension validation can be bypassed entirely via client-controlled rules. Review the CWE definition here: https://cwe.mitre.org/data/definitions/434.html

If the storage disk is configured to be publicly accessible, this can lead to Remote Code Execution (RCE). See the vendor repository: https://github.com/code16/sharp

(Note: Under default configurations, executing uploaded PHP files directly is not possible unless a public disk configuration is in place.)

Patches

This issue has been addressed by removing the client-controlled validation rules and strictly defining upload rules server-side. The fix is available in pull request https://github.com/code16/sharp/pull/714.

Workarounds

Restrict Disk Access: Ensure that the storage disk used for Sharp uploads is strictly private. Under default configurations, an attacker cannot directly execute uploaded PHP files unless a public disk configuration is explicitly used. For more details on Laravel disk configurations, visit: https://laravel.com/docs/13.x/filesystem

Credits

Reported by zaurgsynv.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`code16/sharp`	all versions	9.20.0`composer require code16/sharp:^9.20.0`

Affected Products

1 product · 1 configurations

Application

sharpcode16

< 9.20.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code16/sharp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update code16/sharp to 9.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33687 is resolved across your whole dependency graph.
Workarounds
Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.

Frequently Asked Questions

### Summary The `code16/sharp` Laravel admin panel package contains a vulnerability in its file upload endpoint that allows authenticated users to bypass all file type restrictions. ### Details The upload endpoint within the `ApiFormUploadController` accepts a client-controlled `validation_rule` parameter. This parameter is directly passed into the Laravel validator without sufficient server-side enforcement. By intercepting the request and sending `validation_rule[]=file`, an attacker can completely bypass all MIME type and file extension restrictions. The vulnerable code is located in `src