Slopsmith has path traversal in archive extractors that allows arbitrary file write → potential RCE

published 2026-06-19 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-38056

cvss: 7.6; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits: 0; none known

Slopsmith is a self-contained web application for browsing, playing, and practicing Rocksmith 2014 Custom DLC (CDLC). Prior to 0.2.9-alpha.5, a path-traversal vulnerability in Slopsmith's archive extractors allows an attacker to write arbitrary files outside the extraction directory by supplying a crafted PSARC or sloppak archive. With the default Docker configuration (running as root) and the ability to drop a file into the plugin directory, this escalates to arbitrary remote code execution on the host. Three archive extractors concatenated archive-entry filenames directly onto the extraction root without validation: `lib/psarc.py::unpack_psarc` — PSARC TOC filenames; `lib/patcher.py::unpack_psarc` — duplicate of the above in the patcher flow; `lib/sloppak.py::_unpack_zip` — bare `ZipFile.extractall()` with no member filter. Each accepts entry names containing `..` segments, absolute paths, or backslash separators. The Python `zipfile` module's default `extractall()` is documented as not preventing traversal when callers don't supply a member-filter callback. Version 0.2.9-alpha.5 patches the issue. Until updated, do not open PSARC or sloppak archives from untrusted sources, and do not expose the Slopsmith instance to the public internet. Docker users should also pull the latest image after the next slopsmith Docker image is published.

Patch / fix

links 1

github.com/byrongamatos/slopsmith@9cccac1 commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 4 mo ago (2026-06-22)

Exploit prediction

0.83% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	7.6	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U
CNA	4.0	7.6	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/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

byrongamatos slopsmith

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory
CWE-23 Relative Path Traversal
CWE-36 Absolute Path Traversal

References

Sources

CVE List CVE-2026-49290
NVD CVE-2026-49290

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