CVSS 4.0
9.4 criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HCVE-2026-123815 pyLoad: Tar extraction creates device nodes and FIFOs (member types not filtered; tarfile extractall without filter=)
Critical (9.4) in pyload pyload. EPSS 0.4% estimated probability of exploitation activity in the next 30 days.
On this page
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.
Severity
- EPSS
- 0.4% estimated probability of exploitation activity in the next 30 days; 32nd percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: PoC · Automatable: no · Technical impact: total, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWEs
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory (Path traversal)
CWE-434 Unrestricted Upload of File with Dangerous Type - OWASP Top 10
- A01:2025 Broken Access Control, A06:2025 Insecure Design
- Published
- Modified
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| pyload | < 0.5.0b3.dev102 |
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-fr26-jjhm-638c | PyPI | pyload-ng | <=0.5.0b3.dev101 | no fix published |
Attack patterns (CAPEC)
- CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs Likelihood: High · Severity: High
- CAPEC-64 Using Slashes and URL Encoding Combined to Bypass Validation Logic Likelihood: High · Severity: High
- CAPEC-76 Manipulating Web Input to File System Calls Likelihood: High · Severity: Very High
- CAPEC-78 Using Escaped Slashes in Alternate Encoding Likelihood: High · Severity: High
- CAPEC-79 Using Slashes in Alternate Encoding Likelihood: High · Severity: High
- CAPEC-126 Path Traversal Likelihood: High · Severity: Very High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.
History
- The NVD deferred its analysis
Changes since this site first stored the record. The same for every record: /api/public/changes.