CVE-2026-35187
Published: 06 April 2026
Summary
CVE-2026-35187 is a high-severity SSRF (CWE-918) vulnerability in Pyload-Ng Project Pyload-Ng. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 18.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-35187 is a server-side request forgery (SSRF) vulnerability in pyLoad, a free and open-source download manager written in Python. It affects versions 0.5.0b3.dev96 and earlier, specifically the parse_urls API function in src/pyload/core/api/__init__.py. This function fetches arbitrary URLs server-side using get_url(url) from pycurl without URL validation, protocol restrictions, or IP blacklists, enabling unauthorized access to resources beyond the intended scope. The vulnerability carries a CVSS v3.1 base score of 7.7 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N) and is associated with CWE-918.
An authenticated user with ADD permission can exploit this vulnerability remotely over the network with low complexity and no user interaction required. Attackers can make HTTP/HTTPS requests to internal network resources and cloud metadata endpoints, read local files server-side via the file:// protocol, interact with internal services using gopher:// and dict:// protocols, and enumerate file existence through error-based oracles (distinguishing error 37 from empty responses). This results in high confidentiality impact in a scoped environment, allowing broad internal reconnaissance and data exfiltration.
The GitHub security advisory (GHSA-2wvg-62qm-gj33) and associated commit (4032e57d61d8f864e39f4dcfdb567527a50a9e1f) detail the patch, which adds URL validation and restrictions to prevent arbitrary fetches. Security practitioners should upgrade to a version beyond 0.5.0b3.dev96 incorporating this fix and review access controls for the parse_urls API to limit ADD permissions.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19470
Vulnerability details
pyLoad is a free and open-source download manager written in Python. In 0.5.0b3.dev96 and earlier, the parse_urls API function in src/pyload/core/api/__init__.py fetches arbitrary URLs server-side via get_url(url) (pycurl) without any URL validation, protocol restriction, or IP blacklist. An authenticated user…
more
with ADD permission can make HTTP/HTTPS requests to internal network resources and cloud metadata endpoints, read local files via file:// protocol (pycurl reads the file server-side), interact with internal services via gopher:// and dict:// protocols, and enumerate file existence via error-based oracle (error 37 vs empty response).
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
SSRF in pyLoad parse_urls enables T1190 (exploiting the public API), T1005 (file:// local file reads), T1522 (cloud metadata access), T1018 (internal remote system probing), and T1046 (network service interaction via arbitrary protocols).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Mandates validation of URL inputs to the parse_urls API to block arbitrary fetches to internal resources, local files, or unsupported protocols like file:// and gopher://.
Restricts URL inputs to only permitted protocols, hosts, and schemes, preventing SSRF exploitation via unauthorized internal network access or cloud metadata endpoints.
Requires timely patching of the SSRF flaw in pyLoad versions up to 0.5.0b3.dev96 by applying the fix that implements URL validation and restrictions.