pyLoad: Path Traversal via Package Folder Name in set_package_data

published 2026-05-05 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-29123 , GHSA-838g-gr43-qqg9 , PYSEC-2026-129

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits: 0; none known

pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev100, when passing a folder name in the set_package_data() API function call inside the data object with key "_folder", there is no sanitization at all, allowing a user with Perms.MODIFY to specify arbitrary directories as download locations for a package. This vulnerability is fixed in 0.5.0b3.dev100.

Patch / fix

fixed in 3

pypi pyload-ng 0.5.0b3.dev100
pyload-ng_project pyload-ng 0.5.0b3.dev100
pyload pyload 0.5.0b3.dev100

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-11)

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/pyload/pyload/security/advisories/GHSA-838g-gr43-qqg9 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
GitHub	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
OSV	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
pypi	pyload-ng	<0.5.0b3.dev100	0.5.0b3.dev100

Affected products

pyload pyload

Classification

Weakness

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

References

github.com /pyload/pyload/security/advisories/GHSA-838g-gr43-qqg9
exploit, web, vendor-advisory, evidence
nvd.nist.gov /vuln/detail/CVE-2026-42315
advisory
github.com /pyload/pyload
package
github.com /pypa/advisory-database/tree/main/vulns/pyload-ng/PYSEC-2026-129.yaml
web

Sources

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary