{"id":"CVE-2026-63184","kind":"vulnerability","aliases":["CVE-2026-63184"],"related":[],"title":"Refitter: crafted OpenAPI files cause SSRF and local file disclosure","description":"Refitter is a tool for generating a C# REST API client using the Refit library. Prior to 2.1.1, the `refitter` dotnet tool invokes `NJsonSchema` with unsafe defaults for `$ref` resolution when generating Refit interfaces and contracts from attacker-controlled or attacker-influenced OpenAPI descriptions. Remote `http(s)` references cause requests from the developer or CI host and inline untrusted remote schema content into generated output. Absolute local file paths and relative `../` traversal outside the input directory also resolve and inline local content, permitting arbitrary local-file disclosure. The demonstrated chain stops at server-side request forgery, remote file inclusion, and local file inclusion, not code execution: Refit sets the base URL at runtime, enum values use verbatim-string doubling, and string defaults are escaped. This issue is fixed in version 2.1.1.","summary":"Refitter is a .NET tool that generates C# Refit API clients from OpenAPI files. Before 2.1.1 it resolves attacker-influenced $ref links, so a crafted spec can make the generating machine fetch remote URLs or read local files and copy their contents into the generated code.","severity":"high","cvss":7.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ci","dotnet","openapi","package","refit"],"not_affected_if":["own-reviewed-specs-only","version-2.1.1-or-later"],"how_to_check":"- Check the installed version of the `refitter` dotnet tool, for example with `dotnet tool list`\n- Look for `refitter` in CI pipelines and developer scripts that generate clients from OpenAPI descriptions you do not fully control\n- Review whether generation runs on OpenAPI files from third parties or unreviewed sources","fix":"- `refitter` version `2.1.1` or later, per the source","status":"open","published_at":"2026-10-30T22:16:58+00:00","first_seen_at":"2026-10-30T22:25:57+00:00","triaged_at":"2026-10-30T22:27:11+00:00","updated_at":"2026-10-30T22:27:11+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-30T22:27:11Z","model":"claude-haiku-5-5","output":{"fix":"- `refitter` version `2.1.1` or later, per the source","reach":"unknown","title":"Refitter: crafted OpenAPI files cause SSRF and local file disclosure","impact":"medium","summary":"Refitter is a .NET tool that generates C# Refit API clients from OpenAPI files. Before 2.1.1 it resolves attacker-influenced $ref links, so a crafted spec can make the generating machine fetch remote URLs or read local files and copy their contents into the generated code.","audience":"developers","category":"package","nicknames":[],"who_cares":["dotnet","refit","ci","openapi"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"Local files readable and remote requests made from the generating host","analyst_note":"","how_to_check":"- Check the installed version of the `refitter` dotnet tool, for example with `dotnet tool list`\n- Look for `refitter` in CI pipelines and developer scripts that generate clients from OpenAPI descriptions you do not fully control\n- Review whether generation runs on OpenAPI files from third parties or unreviewed sources","plain_action":"","needs_analyst":false,"not_affected_if":["own-reviewed-specs-only","version-2.1.1-or-later"],"who_is_affected":"Teams that run the refitter dotnet tool on OpenAPI descriptions that come from outside their control, such as third-party specs or user-supplied files, on a developer machine or CI host. Teams that only generate clients from their own reviewed specs in a controlled pipeline are less exposed. The sources say the chain stops at SSRF, remote file inclusion and local file inclusion, not code execution.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.00074,"input_tokens":4311,"output_tokens":617,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-63184':13A,16A '2.1.1':37B,86C,204C 'absolut':136C 'also':147C 'api':31B,78C 'arbitrari':154C 'attack':41B,107C,111C 'attacker-control':106C 'attacker-influenc':40B,110C 'base':182C 'c':29B,76C 'caus':5A,119C 'chain':161C 'ci':17B,125C 'client':32B,79C 'code':68B,177C 'content':64B,132C,152C 'contract':104C 'control':108C 'copi':62B 'craft':2A,47B 'cve':11A,14A 'default':95C,195C 'demonstr':160C 'descript':114C 'develop':123C 'directori':146C 'disclosur':10A,158C 'dotnet':18B,89C 'doubl':192C 'enum':186C 'escap':197C 'execut':178C 'fetch':54B 'file':4A,9A,35B,60B,138C,157C,170C,174C 'fix':201C 'forgeri':168C 'generat':28B,52B,67B,74C,100C,134C 'host':126C 'http':116C 'inclus':171C,175C 'influenc':42B,112C 'inlin':128C,150C 'input':145C 'interfac':102C 'invok':91C 'issu':199C 'librari':83C 'link':44B 'local':8A,59B,137C,151C,156C,173C 'local-fil':155C 'machin':53B 'make':50B 'net':25B 'njsonschema':92C 'openapi':3A,19B,34B,113C 'output':135C 'outsid':143C 'packag':20B 'path':139C 'permit':153C 'prior':84C 'read':58B 'ref':43B,97C 'refer':118C 'refit':21B,30B,82C,101C,179C 'refitt':1A,22B,69C,88C 'relat':141C 'remot':55B,115C,130C,169C 'request':120C,167C 'resolut':98C 'resolv':39B,148C 'rest':77C 'runtim':185C 'schema':131C 'server':165C 'server-sid':164C 'set':180C 'side':166C 'spec':48B 'ssrf':6A 'stop':162C 'string':191C,194C 'tool':26B,72C,90C 'travers':142C 'unsaf':94C 'untrust':129C 'url':56B,183C 'use':80C,188C 'valu':187C 'verbatim':190C 'verbatim-str':189C 'version':203C","nicknames":[],"mitigations":[],"who_affected":"Teams that run the refitter dotnet tool on OpenAPI descriptions that come from outside their control, such as third-party specs or user-supplied files, on a developer machine or CI host. Teams that only generate clients from their own reviewed specs in a controlled pipeline are less exposed. The sources say the chain stops at SSRF, remote file inclusion and local file inclusion, not code execution.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"first_public_at":"2026-10-30T22:16:58+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-63184","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63184","severity":null,"published_at":"2026-10-30T22:16:58+00:00","modified_at":"2026-10-30T22:16:58+00:00","first_seen_at":"2026-10-30T22:25:57+00:00","fetched_at":"2026-10-30T22:25:57+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}