SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-66063

Prior to 2.1.5, the httpserver/updown.go multipart upload handler split part.FileName() on / but did not reject .., allowing an unauthenticated upload with filename .. to create a file outside the served tree.

MEDIUM 6.5EPSS 0.34%

Does this matter?

Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.

Description

goshs is a feature-rich single-binary file server for red teamers and developers. Prior to 2.1.5, the httpserver/updown.go multipart upload handler split part.FileName() on / but did not reject .., allowing an unauthenticated upload with filename .. to create a file outside the served tree. This issue is fixed in version 2.1.5.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS
0.34% probability · 28th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-22
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 0.34%26 October 202626 October 2026

EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.