{"id":"CVE-2026-126410","aliases":["EUVD-2026-125033","GHSA-55h5-m765-f99r","GHSA-hmmr-87qq-258j","RUSTSEC-2026-0420","UBUNTU-CVE-2026-126410"],"status":"published","title":"Wasmtime 48.0.0 before 48.0.8 TOCTOU UDP Send Policy Bypass via wasip3 Sockets","description":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-14","score":0.00161,"percentile":0.05363,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-367"],"published":"2026-10-29T12:00:00Z","modified":"2026-11-14T02:56:04Z","fixes":[{"ecosystem":"crates.io","package":"wasmtime-wasi","fixed_in":["48.0.8","49.0.5","50.0.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"crates.io","package":"wasmtime-wasi","ranges":[{"type":"SEMVER","events":[{"introduced":"48.0.0"},{"fixed":"48.0.8"},{"introduced":"49.0.0"},{"fixed":"49.0.5"},{"introduced":"50.0.0"},{"fixed":"50.0.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"rust-wasmtime","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10.0.1+dfsg-7","15.0.1+dfsg-4","16.0.0+dfsg-2","16.0.0+dfsg-3"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"rust-wasmtime","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["36.0.5+dfsg-1","36.0.13+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"rust-wasmtime","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["26.0.1+dfsg-3","26.0.1+dfsg-4","28.0.1+dfsg-3","29.0.1+dfsg-5","36.0.5+dfsg-1"]}],"products":[{"vendor":"bytecodealliance","product":"wasmtime"}],"references":[{"url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hmmr-87qq-258j","tags":["vendor-advisory","advisory","report"]},{"url":"https://www.vulncheck.com/advisories/wasmtime-48.0.0-before-48.0.8-toctou-udp-send-policy-bypass-via-wasip3-sockets","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126410","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-55h5-m765-f99r"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126410.json","tags":["advisory"]},{"url":"https://crates.io/crates/wasmtime-wasi","tags":["package"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0420.html","tags":["advisory"]},{"url":"https://github.com/bytecodealliance/wasmtime/pull/15077","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2026-126410","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-126410","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-126410","title":"Wasmtime 48.0.0 before 48.0.8 TOCTOU UDP Send Policy Bypass via wasip3 Sockets","description":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.","status":"published","published":"2026-11-13T09:35:41.472Z","modified":"2026-11-13T09:35:41.472Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-367"],"updated_at":"2026-11-13T10:27:12.184616Z"}],"euvd":[{"id":"EUVD-2026-125033","description":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.","status":"published","published":"2026-11-13T09:35:41Z","modified":"2026-11-13T09:35:41Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"updated_at":"2026-11-13T14:38:51.723487Z"}],"ghsa":[{"id":"GHSA-55h5-m765-f99r","title":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0...","description":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.","status":"published","published":"2026-11-13T12:31:22Z","modified":"2026-11-13T12:31:28Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/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","level":"medium"},{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-367"],"updated_at":"2026-11-13T12:50:15.825197Z"}],"nvd":[{"id":"CVE-2026-126410","description":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.","status":"published","published":"2026-11-13T10:17:46.2Z","modified":"2026-11-13T10:17:46.33Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/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","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-367"],"updated_at":"2026-11-13T11:35:38.52146Z"}],"osv":[{"id":"CVE-2026-126410","title":"Wasmtime 48.0.0 before 48.0.8 TOCTOU UDP Send Policy Bypass via wasip3 Sockets","description":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.","status":"published","published":"2026-11-13T09:35:41.472Z","modified":"2026-11-14T02:56:04.28889846Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"cwes":["CWE-367"],"updated_at":"2026-11-14T03:11:06.681237Z"},{"id":"RUSTSEC-2026-0420","title":"wasip3 UDP `send` can deliver a datagram to an address only allowed for receiving","description":"This is an entry in the RustSec database for the Wasmtime security advisory\nlocated at\nhttps://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hmmr-87qq-258j\nFor more information see the GitHub-hosted security advisory.","status":"published","published":"2026-10-29T12:00:00Z","modified":"2026-11-14T02:56:04.28889846Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-14T03:11:06.681237Z"},{"id":"UBUNTU-CVE-2026-126410","description":"Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.","status":"published","published":"2026-11-13T00:00:00Z","modified":"2026-11-13T21:05:25.998212805Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","level":"medium"},{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"updated_at":"2026-11-13T21:30:20.292037Z"}]}}