Description
gpt-crawler through 1.5.1 fails to validate the outputFileName parameter in the POST /crawl endpoint, allowing unauthenticated attackers to write arbitrary files to any filesystem path. Attackers can supply absolute paths or parent-directory segments to overwrite existing files with content sourced from attacker-controlled URLs.
References6
- github.com/BuilderIO/gpt-crawler
- github.com/BuilderIO/gpt-crawler/blob/d2245d66a5ad60bf227a55c84…
- github.com/BuilderIO/gpt-crawler/blob/d2245d66a5ad60bf227a55c84…
- github.com/BuilderIO/gpt-crawler/issues/418
- www.vulncheck.com/advisories/gpt-crawler-arbitrary-file-write-v…
- github.com/BuilderIO/gpt-crawler/issues/418
Metrics
- CVSS 3.1
-
8.6
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - CVSS 4.0
-
8.8
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 45 · as of 8 November 2026
- CWE
- CWE-22
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.