CVE-2026-123815pyload path traversal
CVE-2026-123815 is a path traversal in pyload, rated critical (9.4 on CVSS 4.0).
Why this priority: Critical severity, with no exploitation signal yet.
Published · Updated · NVD status: Deferred
What it is
A file name from the request can climb out of the intended folder with sequences like ../, reaching files the service never meant to expose. Files of dangerous types can be uploaded, and the server may run or serve them.
How it is reached
An attacker can exploit it over the network, with an ordinary user account, and nobody has to click anything.
What an attacker gains
A successful attack can read the data it protects, change data or behaviour and take it offline. In practice, this kind of flaw lets an attacker read or write files outside the folders the service meant to expose. The damage can spread past the vulnerable component into others.
Is it being exploited?
There is no public report of exploitation yet. EPSS estimates a 0.37% chance of exploitation activity in the next 30 days, higher than 32% of scored CVEs.
What to do
- Upgrade pyload to 0.5.0b3.dev102 or later.
- Until it is patched, review who holds accounts that can reach it.
Description from NVD
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.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- File storage the service can read or write. The flaw sits between the application and the file system it can reach.
- Upload endpoints and the storage behind them. The flaw sits between uploaded content and the servers that store or serve it.
Trust boundaries in play
- Authenticated network access. An account is needed, so exposure follows who can sign in: customers, partners or staff.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
- Between the application and the file system it can reach. An attacker who crosses it can read or write files outside the folders the service meant to expose.
- Between uploaded content and the servers that store or serve it. An attacker who crosses it can place a file the server will run or serve to others.
Questions to answer about your own systems
- Where does pyload run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.