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Fencer Intel
critical 9.4

CVE-2026-123815 json

pyLoad: Tar extraction creates device nodes and FIFOs (member types not filtered; tarfile extractall without filter=)

published last mo. modified 2d ago also GHSA-fr26-jjhm-638c , EUVD-2026-120451

cvss
9.4
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev102, UnTar._safe_extractall in src/pyload/plugins/extractors/UnTar.py validates archive member paths and link targets but does not call TarInfo.isdev to reject special tar member types before calling tarfile.extractall. On supported Python 3.9 through 3.13 runtimes, tarfile defaults to the fully_trusted extraction filter, so a user with ADD and STATUS permissions can cause extraction of a crafted archive containing character devices, block devices, or FIFOs. Python 3.14 defaults to a safe extraction filter. When pyLoad runs with operating-system privileges that permit device creation, including the official root-based Docker deployment, the archive can expose raw devices and compromise the host. Non-root deployments can still create FIFOs that cause hangs or IPC confusion. This issue is fixed in version 0.5.0b3.dev102.

Patch / fix

Is CVE-2026-123815 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 9.4 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Affected packages

ecosystem package affected fixed in
pypi pyload-ng
<=0.5.0b3.dev101
 no fix listed

Affected products

  • pyload pyload

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory
  • CWE-434 Unrestricted Upload of File with Dangerous Type

References

Sources

Fencer Intel 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.