pyLoad: Arbitrary File Write via Path Traversal in edit_package()

published 2026-03-05 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-10162 , GHSA-6px9-j4qr-xfjw , PYSEC-2026-121

cvss: 7.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits: 0; none known

pyLoad is a free and open-source download manager written in Python. From version 0.5.0b3.dev13 to 0.5.0b3.dev96, the edit_package() function implements insufficient sanitization for the pack_folder parameter. The current protection relies on a single-pass string replacement of "../", which can be bypassed using crafted recursive traversal sequences. This issue has been patched in version 0.5.0b3.dev97.

Patch / fix

fixed in 3

pypi pyload-ng 0.5.0b3.dev97
pyload-ng_project pyload-ng 0.5.0b3.dev97
pyload pyload 0.5.0b3.dev97

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 8 mo ago (2026-03-09)

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/pyload/pyload/security/advisories/GHSA-6px9-j4qr-xfjw referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
GitHub	3.1	7.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
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.dev13, <0.5.0b3.dev97	0.5.0b3.dev97

Affected products

pyload pyload

Classification

Weakness

CWE-23 Relative Path Traversal

References

github.com /pyload/pyload/security/advisories/GHSA-6px9-j4qr-xfjw
web, exploit, vendor-advisory, evidence
nvd.nist.gov /vuln/detail/CVE-2026-29778
advisory
github.com /pyload/pyload
package
github.com /pypa/advisory-database/tree/main/vulns/pyload-ng/PYSEC-2026-121.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