{"items":[{"id":"NVI-00010714","kind":"vulnerability","title":"Wasmtime: Bit-packing in Cranelift compiler causes silent overflow and miscompilation","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-897f-g5gm-fmxm","CVE-2026-115889"],"plain_summary":"GitHub lists this reviewed advisory for wasmtime, wasmtime. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-3ac4c6087813e019e96e361d78a551d6"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-23T22:02:21.000Z","value":"9.9 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"},{"kind":"EPSS","as_of":"2026-11-01T12:00:16.000Z","value":"0.454%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.39415. Missing scores are unknown.","source_id":"sr-3ac4c6087813e019e96e361d78a551d6"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d","url":"https://github.com/advisories/GHSA-897f-g5gm-fmxm","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-897f-g5gm-fmxm","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:07:08.657Z"},{"id":"sr-3ac4c6087813e019e96e361d78a551d6","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-115889","publisher":"FIRST EPSS","observed_at":"2026-11-01T14:28:32.266Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"],"technology":"wasmtime","known_exclusions":[],"conditions_summary":"## Summary\n\nIn Wasmtime prior to v43, the Cranelift compiler backend bit-packs its SSA value indices in a way that can result in silent overflow in release builds, and result in incorrect value references in the IR resulting in arbitrary miscompilation. A very large Wasm function body, or one that is specially crafted to use many SSA values, can use this to force type-confusion or other arbitrary side-effects and escape the sandbox.\n\nCranelift was changed in Wasmtime v43 to use a full `u32` index, with checks if that limit is exceeded, and so is no longer susceptible to this bug.\n\n## Impact\n\nA Wasmtime engine with default settings (using the Cranelift backend) on any architecture/platform could experience a sandbox escape from a specially-crafted Wasm module.\n\n## Patches\n\nWasmtime v36.0.19 has been released which fixes this issue.","public_affected_ranges":["< 36.0.19"]},{"certainty":"source_listed","source_ids":["sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"],"technology":"wasmtime","known_exclusions":[],"conditions_summary":"## Summary\n\nIn Wasmtime prior to v43, the Cranelift compiler backend bit-packs its SSA value indices in a way that can result in silent overflow in release builds, and result in incorrect value references in the IR resulting in arbitrary miscompilation. A very large Wasm function body, or one that is specially crafted to use many SSA values, can use this to force type-confusion or other arbitrary side-effects and escape the sandbox.\n\nCranelift was changed in Wasmtime v43 to use a full `u32` index, with checks if that limit is exceeded, and so is no longer susceptible to this bug.\n\n## Impact\n\nA Wasmtime engine with default settings (using the Cranelift backend) on any architecture/platform could experience a sandbox escape from a specially-crafted Wasm module.\n\n## Patches\n\nWasmtime v36.0.19 has been released which fixes this issue.","public_affected_ranges":[">= 37.0.0, < 43.0.0"]}],"null_published_at":"2026-11-08T19:53:48.759Z","source_updated_at":"2026-10-23T22:02:21.000Z","source_disclosed_at":"2026-10-23T22:02:20.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T22:07:08.657Z"},{"id":"NVI-00010714","kind":"vulnerability","title":"Wasmtime: Bit-packing in Cranelift compiler causes silent overflow and miscompilation","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-897f-g5gm-fmxm","CVE-2026-115889"],"plain_summary":"GitHub lists this reviewed advisory for wasmtime, wasmtime. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-85611c8cfaf43785c52411c6dd72e6a1"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-23T22:02:21.000Z","value":"9.9 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"},{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.454%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.39421. Missing scores are unknown.","source_id":"sr-85611c8cfaf43785c52411c6dd72e6a1"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d","url":"https://github.com/advisories/GHSA-897f-g5gm-fmxm","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-897f-g5gm-fmxm","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:07:08.657Z"},{"id":"sr-85611c8cfaf43785c52411c6dd72e6a1","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-115889","publisher":"FIRST EPSS","observed_at":"2026-10-31T23:13:27.689Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"],"technology":"wasmtime","known_exclusions":[],"conditions_summary":"## Summary\n\nIn Wasmtime prior to v43, the Cranelift compiler backend bit-packs its SSA value indices in a way that can result in silent overflow in release builds, and result in incorrect value references in the IR resulting in arbitrary miscompilation. A very large Wasm function body, or one that is specially crafted to use many SSA values, can use this to force type-confusion or other arbitrary side-effects and escape the sandbox.\n\nCranelift was changed in Wasmtime v43 to use a full `u32` index, with checks if that limit is exceeded, and so is no longer susceptible to this bug.\n\n## Impact\n\nA Wasmtime engine with default settings (using the Cranelift backend) on any architecture/platform could experience a sandbox escape from a specially-crafted Wasm module.\n\n## Patches\n\nWasmtime v36.0.19 has been released which fixes this issue.","public_affected_ranges":["< 36.0.19"]},{"certainty":"source_listed","source_ids":["sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"],"technology":"wasmtime","known_exclusions":[],"conditions_summary":"## Summary\n\nIn Wasmtime prior to v43, the Cranelift compiler backend bit-packs its SSA value indices in a way that can result in silent overflow in release builds, and result in incorrect value references in the IR resulting in arbitrary miscompilation. A very large Wasm function body, or one that is specially crafted to use many SSA values, can use this to force type-confusion or other arbitrary side-effects and escape the sandbox.\n\nCranelift was changed in Wasmtime v43 to use a full `u32` index, with checks if that limit is exceeded, and so is no longer susceptible to this bug.\n\n## Impact\n\nA Wasmtime engine with default settings (using the Cranelift backend) on any architecture/platform could experience a sandbox escape from a specially-crafted Wasm module.\n\n## Patches\n\nWasmtime v36.0.19 has been released which fixes this issue.","public_affected_ranges":[">= 37.0.0, < 43.0.0"]}],"null_published_at":"2026-11-04T02:53:08.398Z","source_updated_at":"2026-10-23T22:02:21.000Z","source_disclosed_at":"2026-10-23T22:02:20.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T22:07:08.657Z"},{"id":"NVI-00010714","kind":"vulnerability","title":"Wasmtime: Bit-packing in Cranelift compiler causes silent overflow and miscompilation","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-897f-g5gm-fmxm","CVE-2026-115889"],"plain_summary":"GitHub lists this reviewed advisory for wasmtime, wasmtime. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-23T22:02:21.000Z","value":"9.9 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d","url":"https://github.com/advisories/GHSA-897f-g5gm-fmxm","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-897f-g5gm-fmxm","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:07:08.657Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"],"technology":"wasmtime","known_exclusions":[],"conditions_summary":"## Summary\n\nIn Wasmtime prior to v43, the Cranelift compiler backend bit-packs its SSA value indices in a way that can result in silent overflow in release builds, and result in incorrect value references in the IR resulting in arbitrary miscompilation. A very large Wasm function body, or one that is specially crafted to use many SSA values, can use this to force type-confusion or other arbitrary side-effects and escape the sandbox.\n\nCranelift was changed in Wasmtime v43 to use a full `u32` index, with checks if that limit is exceeded, and so is no longer susceptible to this bug.\n\n## Impact\n\nA Wasmtime engine with default settings (using the Cranelift backend) on any architecture/platform could experience a sandbox escape from a specially-crafted Wasm module.\n\n## Patches\n\nWasmtime v36.0.19 has been released which fixes this issue.","public_affected_ranges":["< 36.0.19"]},{"certainty":"source_listed","source_ids":["sr-c0bdce4a1ec1da0fa2a6da6a0f0b035d"],"technology":"wasmtime","known_exclusions":[],"conditions_summary":"## Summary\n\nIn Wasmtime prior to v43, the Cranelift compiler backend bit-packs its SSA value indices in a way that can result in silent overflow in release builds, and result in incorrect value references in the IR resulting in arbitrary miscompilation. A very large Wasm function body, or one that is specially crafted to use many SSA values, can use this to force type-confusion or other arbitrary side-effects and escape the sandbox.\n\nCranelift was changed in Wasmtime v43 to use a full `u32` index, with checks if that limit is exceeded, and so is no longer susceptible to this bug.\n\n## Impact\n\nA Wasmtime engine with default settings (using the Cranelift backend) on any architecture/platform could experience a sandbox escape from a specially-crafted Wasm module.\n\n## Patches\n\nWasmtime v36.0.19 has been released which fixes this issue.","public_affected_ranges":[">= 37.0.0, < 43.0.0"]}],"null_published_at":"2026-10-31T22:27:12.377Z","source_updated_at":"2026-10-23T22:02:21.000Z","source_disclosed_at":"2026-10-23T22:02:20.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T22:07:08.657Z"}],"next_cursor":null,"snapshot_revision":"42594"}