{"id":"CVE-2026-8257","aliases":["DEBIAN-CVE-2026-8257","EUVD-2026-29013","GHSA-gmmj-chcc-2f2x","JLSEC-2026-1094","UBUNTU-CVE-2026-8257","openSUSE-SU-2026:11915-1"],"status":"published","title":"WebAssembly Binaryen BrOn wasm-ir-builder.cpp makeBrOn assertion","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","severity":{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00159,"percentile":0.05126,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-617"],"published":"2026-05-11T00:30:13Z","modified":"2026-11-03T21:00:07Z","fixes":[{"ecosystem":"Debian:14","package":"binaryen","fixed_in":["130-2"],"sources":["osv"]},{"ecosystem":"Julia","package":"Binaryen_jll","fixed_in":["0.130.0+0"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["108-1","112-1","116-1","120-1","120-2","120-3","120-4","120-4+ports","122-1.1","122-2","122-3","130-1","130-2","130-3","131-1","131-2"]},{"source":"osv","ecosystem":"Debian:13","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["120-4","120-4+ports","122-1.1","122-2","122-3","130-1","130-2","130-3","131-1","131-2"]},{"source":"osv","ecosystem":"Debian:14","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"130-2"}]}],"versions":["120-4","120-4+ports","122-1.1","122-2","122-3","130-1"]},{"source":"osv","ecosystem":"Julia","package":"Binaryen_jll","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.130.0+0"}]}]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["89-1","90-1","91-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["99-3","105-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["108-1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["120-3","120-4"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["120-4build1","130-2","130-3","131-2"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["120-4","120-4build1"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"binaryen","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"133-1.1"}]}],"bundled":3}],"products":[{"vendor":"webassembly","product":"binaryen"}],"references":[{"url":"https://vuldb.com/vuln/362554","tags":["vdb-entry","technical-description","Third Party Advisory","VDB Entry","advisory","web"]},{"url":"https://vuldb.com/vuln/362554/cti","tags":["signature","permissions-required","Permissions Required","VDB Entry","report","web"]},{"url":"https://vuldb.com/submit/809552","tags":["third-party-advisory","Third Party Advisory","VDB Entry","advisory","web"]},{"url":"https://github.com/WebAssembly/binaryen/issues/8633","tags":["issue-tracking","Exploit","Issue Tracking","Third Party Advisory","report","web"]},{"url":"https://github.com/WebAssembly/binaryen/pull/8635","tags":["issue-tracking","patch","Mitigation","Patch","fix","web"]},{"url":"https://github.com/HackC0der/CVE-Repos/blob/main/wasm-binaryen/Assertion_Failure_isRef_wasm_Type_getHeapType_commit_3ef8d19","tags":["exploit","patch","Exploit","fix","web"]},{"url":"https://github.com/WebAssembly/binaryen/commit/1251efbc1ea471c1311d2726b2bbe061ff2a291c","tags":["patch","Patch","fix","web"]},{"url":"https://github.com/WebAssembly/binaryen/","tags":["product","Product","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8257","tags":["advisory","web"]},{"url":"https://github.com/WebAssembly/binaryen","tags":["web"]},{"url":"https://github.com/advisories/GHSA-gmmj-chcc-2f2x","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8257.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-8257","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-8257","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-8257","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2025-14956","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-14957","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-8257","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2026-8257","title":"WebAssembly Binaryen BrOn wasm-ir-builder.cpp makeBrOn assertion","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-05-11T00:30:13.661Z","modified":"2026-05-11T17:31:23.327Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P","level":"medium","assessor":"cna"},{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C","level":"low","assessor":"cna"},{"version":"3.0","score":3.3,"vector":"CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C","level":"low","assessor":"cna"},{"version":"2.0","score":1.7,"vector":"AV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:OF/RC:C","assessor":"cna"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T13:48:13.398044Z"}],"euvd":[{"id":"EUVD-2026-29013","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-05-11T00:30:13Z","modified":"2026-05-11T17:31:23Z","cvss":[{"version":"4.0","score":4.8,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P","level":"medium"}],"updated_at":"2026-11-02T19:05:10.736891Z"}],"ghsa":[{"id":"GHSA-gmmj-chcc-2f2x","title":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function...","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-05-11T03:31:31Z","modified":"2026-05-11T03:31:38Z","cvss":[{"version":"4.0","score":1.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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":"low"},{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T15:07:58.760928Z"}],"nvd":[{"id":"CVE-2026-8257","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-05-11T02:16:27.09Z","modified":"2026-07-23T20:10:00.13Z","cvss":[{"version":"4.0","score":1.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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":"low","assessor":"secondary"},{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"secondary"},{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":1.7,"vector":"AV:L/AC:L/Au:S/C:N/I:N/A:P","level":"low","assessor":"secondary"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T14:12:18.239974Z"}],"osv":[{"id":"CVE-2026-8257","title":"WebAssembly Binaryen BrOn wasm-ir-builder.cpp makeBrOn assertion","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-05-11T00:30:13.661Z","modified":"2026-10-28T11:18:41.119279069Z","cvss":[{"version":"4.0","score":1.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P","level":"low"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T15:45:18.131258Z"},{"id":"DEBIAN-CVE-2026-8257","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-05-11T02:16:27.09Z","modified":"2026-11-03T21:00:07.570714764Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T21:05:16.218603Z"},{"id":"JLSEC-2026-1094","title":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function...","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-07-31T20:09:46.097Z","modified":"2026-07-31T20:20:44.709132056Z","cvss":[{"version":"2.0","score":1.7,"vector":"AV:L/AC:L/Au:S/C:N/I:N/A:P","level":"low"},{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"},{"version":"4.0","score":1.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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":"low"}],"updated_at":"2026-11-02T15:47:18.159338Z"},{"id":"UBUNTU-CVE-2026-8257","description":"A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.","status":"published","published":"2026-05-11T02:16:00Z","modified":"2026-10-17T13:01:11.350906572Z","cvss":[{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"low"},{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"},{"version":"4.0","score":1.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P","level":"low"}],"updated_at":"2026-11-02T16:57:22.213888Z"},{"id":"openSUSE-SU-2026:11915-1","title":"binaryen-133-1.1 on GA media","description":"These are all security issues fixed in the binaryen-133-1.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2026-09-29T00:00:00Z","modified":"2026-09-30T18:23:13.875512892Z","updated_at":"2026-11-02T16:58:40.245664Z"}]}}