Skip to content
Fencer Vulns
high 8.1

CVE-2026-34783 json

Ferret has a Path Traversal in IO::FS::WRITE allows arbitrary file write when scraping malicious websites

published 2026-04-01 7 mo ago modified 2026-10-23 16 d ago also GHSA-j6v5-g24h-vg4j , GO-2026-5452 , EUVD-2026-19353

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

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 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.

Patch / fix

  • go github.com/MontFerret/ferret/v2 2.0.0-alpha.4
  • montferret ferret 2.0.0
  • govulncheck-vulndb SLES 16.0, SLES for SAP applications 16.0 0.0.20260727T201416-160000.1.1

suse advisories SUSE-SU-2026:23216-1SUSE-SU-2026:23227-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260727T201416-160000.1.1

opensuse advisories openSUSE-SU-2026:21551-1

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
7 mo ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/MontFerret/ferret/security/advisories/GHSA-j6v5-g24h-vg4j referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
GitHub 3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

Affected packages

ecosystem package affected fixed in
go github.com/MontFerret/ferret/v2
<2.0.0-alpha.4
2.0.0-alpha.4
go github.com/MontFerret/ferret
<=0.18.1
 no fix listed

Affected products

  • MontFerret ferret

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory
  • CWE-73 External Control of File Name or Path

References

Sources

Fencer Vulns 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.