ShaneIsrael fireshare 1.5.2 checkSum path traversal

Summaryinfo

A vulnerability has been found in ShaneIsrael fireshare 1.5.2 and classified as critical. This vulnerability affects unknown code. The manipulation of the argument checkSum leads to path traversal. This vulnerability is documented as CVE-2026-33645. The attack can be initiated remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in ShaneIsrael fireshare 1.5.2 and classified as critical. This issue affects an unknown part. The manipulation of the argument checkSum with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Fireshare facilitates self-hosted media and link sharing. In version 1.5.1, an authenticated path traversal vulnerability in Fireshare’s chunked upload endpoint allows an attacker to write arbitrary files outside the intended upload directory. The `checkSum` multipart field is used directly in filesystem path construction without sanitization or containment checks. This enables unauthorized file writes to attacker-chosen paths writable by the Fireshare process (e.g., container `/tmp`), violating integrity and potentially enabling follow-on attacks depending on deployment. Version 1.5.2 fixes the issue.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-33645 since 03/23/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

Upgrading to version 1.5.2 eliminates this vulnerability. The upgrade is hosted for download at github.com.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• ShaneIsrael

Name

• fireshare

Version

• 1.5.2

Website

• Product: https://github.com/ShaneIsrael/fireshare/

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion