Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-34783 is a high-severity Path Traversal (CWE-22) vulnerability in Montferret Ferret. Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 43th 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 map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-34783 is a path traversal vulnerability (CWE-22, CWE-73) in the IO::FS::WRITE standard library function of Ferret, a declarative system for working with web data. Versions of Ferret prior to 2.0.0-alpha.4 are affected, enabling attackers to write arbitrary files to the filesystem of the machine running Ferret. The issue arises when scraped web content includes filenames with path traversal sequences like "../", which are then used to construct output paths in common scraping workflows.
An attacker who controls a malicious website can exploit this by embedding "../" sequences in filenames returned during a scrape. A Ferret operator must scrape the site and naively incorporate those attacker-supplied filenames into output paths, requiring user interaction but no privileges (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H, score 8.1). This grants control over both the destination path and file content, allowing arbitrary file writes that can achieve remote code execution, such as by targeting cron jobs, SSH authorized_keys, shell profiles, or web shells.
The vulnerability is fixed in Ferret version 2.0.0-alpha.4, as detailed in the project's GitHub security advisory (GHSA-j6v5-g24h-vg4j) and the patching commit (160ebad6bd50f153453e120f6d909f5b83322917). Security practitioners should advise users to upgrade immediately and review scraping scripts for unsanitized filename handling from untrusted sources.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19353
Vulnerability Data
Ferret is a declarative system for working with web data. Prior to 2.0.0-alpha.4, a path traversal vulnerability in Ferret's IO::FS::WRITE standard library function allows a malicious website to write arbitrary files to the filesystem of the machine running Ferret. When…
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an operator scrapes a website that returns filenames containing ../ sequences, and uses those filenames to construct output paths (a standard scraping pattern), the attacker controls both the destination path and the file content. This can lead to remote code execution via cron jobs, SSH authorized_keys, shell profiles, or web shells. This vulnerability is fixed in 2.0.0-alpha.4.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly neutralizes special path elements before pathname construction occurs.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Least-privilege file authorization directly limits damage from externally controlled paths.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
Secure SDLC practices include input validation and path sanitization that eliminate this weakness.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Security testing in development catches path traversal via static/dynamic analysis.
Information access restriction limits which files an application may read or write.