{"items":[{"id":"NVI-00011870","kind":"vulnerability","title":"Wasmtime: WASI hard links bypass wasmtime-wasi's FilePerms for destination","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4ch3-9j33-3pmj","CVE-2026-58494"],"plain_summary":"GitHub lists this reviewed advisory for wasmtime-wasi, wasmtime-wasi, wasmtime-wasi, wasmtime-wasi. 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-1a320a6fbbd2b0b0d2eee8846dfb1199"],"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":"2026-10-16T19:57:30.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-4a422c6ed45d3ad6b22f1359295ff2b2"},{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.171%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.06463. Missing scores are unknown.","source_id":"sr-1a320a6fbbd2b0b0d2eee8846dfb1199"}],"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-4a422c6ed45d3ad6b22f1359295ff2b2","url":"https://github.com/advisories/GHSA-4ch3-9j33-3pmj","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4ch3-9j33-3pmj","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:14.588Z"},{"id":"sr-1a320a6fbbd2b0b0d2eee8846dfb1199","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-2026-58494","publisher":"FIRST EPSS","observed_at":"2026-11-01T01:39:43.082Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":["< 24.0.11"]},{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":[">= 25.0.0, < 36.0.12"]},{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":[">= 37.0.0, < 45.0.3"]},{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":[">= 46.0.0, < 46.0.1"]}],"null_published_at":"2026-11-01T14:34:14.101Z","source_updated_at":"2026-10-16T19:57:30.000Z","source_disclosed_at":"2026-10-16T19:57:26.000Z","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":"2026-10-31T23:14:14.588Z"},{"id":"NVI-00011870","kind":"vulnerability","title":"Wasmtime: WASI hard links bypass wasmtime-wasi's FilePerms for destination","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4ch3-9j33-3pmj","CVE-2026-58494"],"plain_summary":"GitHub lists this reviewed advisory for wasmtime-wasi, wasmtime-wasi, wasmtime-wasi, wasmtime-wasi. 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-4a422c6ed45d3ad6b22f1359295ff2b2"],"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":"2026-10-16T19:57:30.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-4a422c6ed45d3ad6b22f1359295ff2b2"}],"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-4a422c6ed45d3ad6b22f1359295ff2b2","url":"https://github.com/advisories/GHSA-4ch3-9j33-3pmj","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4ch3-9j33-3pmj","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:14.588Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":["< 24.0.11"]},{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":[">= 25.0.0, < 36.0.12"]},{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":[">= 37.0.0, < 45.0.3"]},{"certainty":"source_listed","source_ids":["sr-4a422c6ed45d3ad6b22f1359295ff2b2"],"technology":"wasmtime-wasi","known_exclusions":[],"conditions_summary":"## Summary\n\nWasmtime's WASI filesystem implementation lets a guest with a read-only source file capability overwrite that file by hard-linking it into another preopen that allows file writes. An attacker who can run a WASI guest can bypass `WasiCtxBuilder` per-preopen `FilePerms` and modify host files that were exposed as `FilePerms::READ`.\n\nThis attack is possible through the wasip1, wasip2, and wasip3 interfaces to the WASI filesystem.\n\nThis attack is also possible through an indirection of renaming a hardlink into another preopen.\n\n### Details\n\n`WasiCtxBuilder::preopened_dir` documents `file_perms` as the maximum permissions usable for files in that preopen. However, hard-link creation and renaming only checked directory mutation for permission, and not whether the file permissions matched.\n\nThis makes an attack possible where:\n* a read-only file `target` exists in a preopen with only FilePerms::READ\n* a hardlink named `alias`, with destination to the `target`, is created in a preopen with FilePerms::READ | FilePerms::WRITE\n* the attacker opens the file `alias` for writing, in which they can overwrite `target`\n\nThe same attack is possible by way of renaming:\n* a read-only file `","public_affected_ranges":[">= 46.0.0, < 46.0.1"]}],"null_published_at":"2026-11-01T01:03:56.611Z","source_updated_at":"2026-10-16T19:57:30.000Z","source_disclosed_at":"2026-10-16T19:57:26.000Z","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":"2026-10-31T23:14:14.588Z"}],"next_cursor":null,"snapshot_revision":"42594"}