Streambert: Arbitrary Directory Creation and File Manipulation via Backup Handler

published 2026-08-18 2 mo ago modified 2026-10-22 17 d ago also EUVD-2026-62199

cvss: 8.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits: 0; none known

Streambert is a cross-platform Electron Desktop App to stream and download video content. Prior to 2.6.0, the perform-scheduled-backup IPC handler in src/ipc/storage.js takes settings.path from a renderer-supplied object and uses the resulting directory for fs.mkdirSync, fs.writeFileSync, fs.readdirSync, and fs.unlinkSync operations without checking that it is inside an authorized backup location. A compromised renderer can choose an absolute path or a relative traversal path to create directories and write a streambert-backup-[timestamp].json file containing renderer-controlled data. The pruning loop can also delete files in that directory whose names begin with streambert-backup- and end with .json. This vulnerability is fixed in 2.6.0.

Patch / fix

links 2

github.com/truelockmc/streambert@43566ed commit
github.com/truelockmc/streambert#149 pull request

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 2 mo ago (2026-08-25)

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/truelockmc/streambert/security/advisories/GHSA-c64m-cx97-6rc9 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.4	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:L/SI:H/SA:H
CNA	4.0	8.4	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:L/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

truelockmc streambert

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory
CWE-73 External Control of File Name or Path

References

Sources

CVE List CVE-2026-52875
NVD CVE-2026-52875

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary