{"id":"CVE-2026-119130","kind":"vulnerability","aliases":["CVE-2026-119130"],"related":[],"title":"Wasmtime: WASI HTTP guests can reach hosts outside embedder allowlists","description":"Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 does not verify that set-path-with-query values in wasmtime-wasi-http are paths, so absolute-form URLs are written verbatim as the HTTP/1.1 request target while the connection uses the allowed authority. A malicious guest can supply an absolute URL that a forward proxy or gateway at that authority honors, reaching hosts disallowed by embedder filtering policies.","summary":"Wasmtime's wasmtime-wasi-http does not check that set-path-with-query values are paths, so absolute-form URLs are sent as the HTTP/1.1 request target. A malicious guest can use this to make a forward proxy or gateway reach hosts the embedder's filtering policy disallows.","severity":"low","cvss":2.6,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["runtime","wasi-http","wasmtime","webassembly"],"not_affected_if":["no-forward-proxy","no-untrusted-guests","no-wasi-http"],"how_to_check":"- Check the Wasmtime version in use, e.g. `wasmtime --version`, and compare it against the affected ranges below.\n- Look for embedders that use wasmtime-wasi-http and rely on outbound host allowlists or forward proxies.","fix":"- `wasmtime` before `36.0.18` fixed to `36.0.18`\n- `wasmtime` `37.0.0` before `48.0.6` fixed to `48.0.6`\n- `wasmtime` `49.0.0` before `49.0.3` fixed to `49.0.3`","status":"open","published_at":"2026-10-29T16:18:05+00:00","first_seen_at":"2026-10-29T16:25:58+00:00","triaged_at":"2026-10-29T16:32:12+00:00","updated_at":"2026-10-29T16:32:12+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-10-29T16:32:12Z","model":"claude-haiku-5-5","output":{"fix":"- `wasmtime` before `36.0.18` fixed to `36.0.18`\n- `wasmtime` `37.0.0` before `48.0.6` fixed to `48.0.6`\n- `wasmtime` `49.0.0` before `49.0.3` fixed to `49.0.3`","reach":"network","title":"Wasmtime: WASI HTTP guests can reach hosts outside embedder allowlists","impact":"medium","summary":"Wasmtime's wasmtime-wasi-http does not check that set-path-with-query values are paths, so absolute-form URLs are sent as the HTTP/1.1 request target. A malicious guest can use this to make a forward proxy or gateway reach hosts the embedder's filtering policy disallows.","audience":"developers","category":"runtime","nicknames":[],"who_cares":["wasmtime","webassembly","wasi-http"],"confidence":0.7,"fix_status":"available","needs_auth":"unknown","worst_case":"Guest reaches hosts outside embedder egress filtering policy.","analyst_note":"","how_to_check":"- Check the Wasmtime version in use, e.g. `wasmtime --version`, and compare it against the affected ranges below.\n- Look for embedders that use wasmtime-wasi-http and rely on outbound host allowlists or forward proxies.","plain_action":"","needs_analyst":false,"not_affected_if":["no-untrusted-guests","no-wasi-http","no-forward-proxy"],"who_is_affected":"Applications that embed Wasmtime and run untrusted WebAssembly guests using wasmtime-wasi-http with outbound HTTP, especially where a forward proxy or gateway sits behind the allowed authority. Teams that do not run untrusted guests or do not use wasi-http outbound requests can likely skip it.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"low"},"cost_usd":0.000753,"input_tokens":4213,"output_tokens":664,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-119130':13A,16A '-2026':12A,15A '36.0.18':76C '37.0.0':77C '48.0.6':79C '49.0.0':81C '49.0.3':83C 'absolut':43B,103C,127C 'absolute-form':42B,102C 'allow':119C 'allowlist':10A 'author':120C,137C 'check':31B 'connect':116C 'cve':11A,14A 'disallow':73B,141C 'embedd':9A,69B,143C 'filter':71B,144C 'form':44B,104C 'forward':62B,131C 'gateway':65B,134C 'guest':4A,55B,123C 'honor':138C 'host':7A,67B,140C 'http':3A,20B,28B,98C 'http/1.1':50B,111C 'make':60B 'malici':54B,122C 'outsid':8A 'path':35B,40B,90C,100C 'polici':72B,145C 'proxi':63B,132C 'queri':37B,92C 'reach':6A,66B,139C 'request':51B,112C 'runtim':17B 'sent':47B 'set':34B,89C 'set-path-with-queri':33B,88C 'suppli':125C 'target':52B,113C 'url':45B,105C,128C 'use':57B,117C 'valu':38B,93C 'verbatim':108C 'verifi':86C 'wasi':2A,19B,27B,97C 'wasi-http':18B 'wasmtim':1A,21B,23B,26B,74C,96C 'wasmtime-wasi-http':25B,95C 'webassembl':22B 'written':107C","nicknames":[],"mitigations":[],"who_affected":"Applications that embed Wasmtime and run untrusted WebAssembly guests using wasmtime-wasi-http with outbound HTTP, especially where a forward proxy or gateway sits behind the allowed authority. Teams that do not run untrusted guests or do not use wasi-http outbound requests can likely skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"first_public_at":"2026-10-29T16:18:05+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:L/VI:N/VA:N/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","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-119130","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119130","severity":null,"published_at":"2026-10-29T16:18:05+00:00","modified_at":"2026-10-29T16:18:06+00:00","first_seen_at":"2026-10-29T16:25:58+00:00","fetched_at":"2026-10-29T16:25:58+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"}